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BACKGROUND Exaggerated sympathetic cardiovascular (CV) reactivity to stress associates with elevated risk for clinical and preclinical end points of CV disease. It would be useful to identify these individuals, preferably from feasible measurements commonly used in health care. Our study examined the association between home blood pressure (BP) variability and cardiac workload response to whole-body cold exposure. METHODS Seventy-five men (55–65 years, 46 hypertensive) measured BP at home twice in the morning and evening for a week. We computed systolic home BP variability as SD of daily means and divided the subjects into groups demonstrating either high or low BP variability. They were exposed to whole-body cold exposure (−10 °C, wind 3 m/second, 15 minutes, winter clothes, standing). BP and heart rate were measured at 3-minute intervals during, and 15 minutes before and after the exposure. Rate-pressure product (RPP) was calculated to represent cardiac workload. RESULTS Subjects with high systolic home BP variability demonstrated a greater RPP increase in cold conditions compared to those with low BP variability [mean change from baseline (95% CI): 1,850 (1,450 to 2,250) bpm × mm Hg vs. 930 (610, 1,250) bpm × mm Hg, P < 0.01]. This was related to the augmented systolic BP change [31(28, 35) mm Hg vs. 23(20, 26) mm Hg, P < 0.01]. Home BP variability correlated with cold-related RPP (rS = 0.34, P = 0.003) and systolic BP (rS = 0.38, P < 0.001) responses. CONCLUSIONS Moderate whole-body cold exposure increased BP and cardiac workload more among those with higher systolic home BP variability, independently of home BP level. Elevated home BP variability may indicate augmented sympathetically mediated vascular reactivity for environmental stressors. PUBLIC TRIALS REGISTRY NUMBER Trial Number NCT02007031.

Hand-arm vibration (HAV) from hand-held vibrating machines increases the risk of injury in the form of vasoconstriction in the fingers, commonly named as vibration induced white fingers (VWF). Cold temperature may increase that risk. This experimental study examined and compared the effects of the skin temperature of the hands during and after exposure to HAV in thermoneutral and cold conditions. Fourteen subjects were exposed to three conditions: 25°C with HAV, 5°C with HAV or 5°C without HAV. Their skin temperatures were continuously recorded for the thumbs, index fingers, palms, and back of hands. After 20 min of acclimatization, the subjects held, for five min, two handles where the right handle could vibrate at 5 m/s2 and the left was stationary. Finally, they released their grip and stood still for 10 more min. HAV had no additional cooling effect in cold during gripping of the handles. After the subjects released the handles there was only a HAV-induced cooling effect in the left palm with on average 0.5°C colder skin temperature. A single exposure to HAV will not cause an injury such as VWF, but as the present study show: short-term exposure to HAV causes some changes in skin temperature.

It is vital to protect divers from the cold, particularly in Arctic conditions. The insulating gas layer within the drysuit is crucial for reducing heat loss. The technical diving community has long claimed the superiority of argon over air as an insulating gas. Although argon is widely used, previous studies have shown no significant differences between the two gases. Owing to its lower heat conductivity, argon should be a better thermal insulating gas than air.The study aimed to determine whether argon is beneficial for reducing heat loss in divers during development of military drysuit diving equipment in Arctic water temperatures. Four divers completed 14 dives, each lasting 45 minutes: seven dives used air insulation and seven used argon insulation. Rectal and eight skin temperatures were measured from which changes in calculated mean body temperature (MBT) were assessed.There was a significant reduction in area weighted skin temperature over time (0-45 minute) on air dives (ΔTskin = -4.16°C, SE = 0.445, P ⟨ 0.001). On argon dives the reduction was significantly smaller compared to air dives (difference between groups = 2.26°C, SE = 0.358, P ⟨ 0.001). There were no significant changes in rectal temperatures, nor was a significant difference seen between groups.Compared to air, argon may be superior as a drysuit insulating gas in Arctic water temperatures for some divers. Argon used as insulating gas can make diving safer and may diminish the risks of fatal diving accidents and occupational hazard risks in professional diving.

Skin and core tissue cooling modulates skeletal muscle oxygenation at rest. Whether tissue cooling also influences the skeletal muscle deoxygenation response during exercise is unclear. We evaluated the effects of skin and core tissue cooling on skeletal muscle blood volume and deoxygenation during sustained walking and running. Eleven male participants walked or ran six times on a treadmill for 60 min in ambient temperatures of 22°C (Neutral), 0°C for skin cooling (Cold 1), and at 0°C following a core and skin cooling protocol (Cold 2). Difference between oxy/deoxygenated haemoglobin ([diffHb]: deoxygenation index) and total haemoglobin content ([tHb]: total blood volume) in the vastus lateralis (VL) muscle was measured continuously. During walking, lower [tHb] was observed at 1 min in Cold 1 and Cold 2 vs. Neutral (P˂0.05). Lower [diffHb] was seen at 1 and 10 min in Cold 2 vs. Neutral by 13.5 ± 1.2 µM and 15.3 ± 1.4 µM and Cold 1 by 10.4 ± 3.1 µM and 11.1 ± 4.1 µM, respectively (P˂0.05). During running, [tHb] was lower in Cold 2 vs. Neutral at 10 min only (P = 0.004). [diffHb] was lower at 1 min in Cold 2 by 11.3 ± 3.1 µM compared to Neutral and by 13.5 ± 2.8 µM compared to Cold 1 (P˂0.001). Core tissue cooling, prior to exercise, induced greater deoxygenation of the VL muscle during the early stages of exercise, irrespective of changes in blood volume. Skin cooling alone, however, did not influence deoxygenation of the VL during exercise.

Regular year-round exercise is recommended for patients with coronary artery disease (CAD). However, the combined effects of cold and moderate sustained exercise, both known to increase cardiac workload, on cardiovascular responses are not known. We tested the hypothesis that cardiac workload is increased, and evidence of ischemia would be observed during exercise in the cold in patients with CAD. Sixteen men (59.3 +/- 7.0 yr, means +/- SD) with stable CAD each underwent 4, 30 min exposures in a randomized order: seated rest and moderate-intensity exercise [walking, 60%-70% of max heart rate (HR)] performed at +22 degrees C and -15 degrees C. Systolic brachial blood pressure (SBP), HR, electrocardiogram (ECG), and skin temperatures were recorded throughout the intervention. Rate pressure product (RPP) and ECG parameters were obtained. The combined effects of cold and submaximal exercise were additive for SBP and RPP and synergistic for HR when compared with rest in a neutral environment. RPP (mmHg.beats/min) was 17% higher during exercise in the cold (18,080 +/- 3540) compared with neutral (15,490 +/- 2,940) conditions (P = 0.001). Only a few ST depressions were detected during exercise but without an effect of ambient temperature. The corrected QT interval increased while exercising in the cold compared with neutral temperature (P = 0.023). Recovery of postexercise blood pressure was similar regardless of temperature. Whole body exposure to cold during submaximal exercise results in higher cardiac workload compared with a neutral environment. Despite the higher RPP, no signs of myocardial ischemia or abnormal ECG responses were observed. The results of this study are useful for planning year-round exercise-based rehabilitation programs for stable CAD patients.

Background: The occurrence of subjective symptoms related to heat strain in the general population is unknown. The present study aimed to describe the temperatures considered to be comfortable or hot and the prevalence of heat-related complaints and symptoms in the Finnish population. Methods: Four thousand and seven men and women aged 25–74 years, participants of the National FINRISK 2007 study, answered a questionnaire inquiring about the ambient temperatures considered to be hot and the upper limit of comfortable and about heat-related complaints and symptoms. The age trends in threshold temperatures and symptom prevalence were examined in 1-year groups by gender after smoothing with loess regression. The prevalence estimates were also adjusted for age. Results: The temperature considered as hot averaged 26°C and the upper limit for thermal comfort was 22°C. Both temperatures declined with age (from 25 to 74 years) by 1–5°C. Approximately 80% of the subjects reported signs or symptoms of heat strain in warm weather, mostly thirst (68%), drying of mouth (43%), impaired endurance (43%) and sleep disturbances (32%). Cardiac and respiratory symptoms were reported by 6 and 7%, respectively, and their prevalence increased up to the age of 75 years. The exception was thirst, whose prevalence declined with age. Most symptoms and complaints were more prevalent in women than men. Conclusions: A large percentage of this northern European population suffers from heat-related complaints. Information on these is an aid in assessing the burden of summer heat on population health and is a prerequisite for any rational planning of pre-emptive measures.

BACKGROUND Short- and long-term exposures to cold increase blood pressure and may explain the higher wintertime cardiovascular morbidity and mortality. Hypertensive subjects may be more susceptible to adverse cold-related cardiovascular health effects. The aim of our study was to assess the effect of short-term cold exposure on central aortic blood pressure among untreated hypertensive men. METHODS We conducted a population-based recruitment of 41 hypertensive men and a control group of 20 men without hypertension (aged 55-65 years) who underwent whole-body cold exposure (15-minute exposure to temperature -10 °C, wind 3 m/s, winter clothes). Central aortic blood pressure, augmentation index, and subendocardial viability ratio were measured by radial artery applanation tonometry. RESULTS Short-term cold exposure increased the central aortic blood pressure similarly both in both hypertensive men, from 130/93 to 162/107 mm Hg (P < 0.001) and men in the control group, from 114/81 to 142/91 mmHg (P < 0.001). Augmentation index increased by 12% (from 10% to 22%, P < 0.001; and from 16% to 28%, P < 0.001, respectively), whereas subendocardial viability ratio decreased 10% (from 188% to 177%, P = 0.001; and from 203% to 193%, P = 0.01, respectively) during cold exposure in both hypertensive men and control subjects. CONCLUSIONS Short-term cold exposure increases central aortic blood pressure and cardiac workload, and myocardial oxygen demand slightly increases in relation to blood supply in untreated hypertensive middle-aged men. Because of the higher baseline blood pressure among hypertensive subjects, the cold-induced rise in central aortic blood pressure may increase the risk of adverse cardiovascular health effects.

Background Exposure to cold reportedly increases musculoskeletal pains. We assessed the prevalence of such pain and self-reported threshold temperature (TT) at which the pain emerges. Methods A random sample of 6591 people in Finland, aged 25–74 years, answered a questionnaire on repeated cold-related musculoskeletal pain (CMP) and its TT. The response rate was 64%. We used quantile regression to quantify the effects of personal characteristics and region of residence on TT at various locations of its distribution. Results Of the participants, 1892 (30%) experienced CMP in at least one body site and 1692 reported TT. Ten percent of the participants who perceived CMP did so at −2 °C, 50% at −14 °C and 90% at −23 °C. Residence in the South elevated TT by 1–6 °C compared with residence in the North, depending on the proportion of participants reporting CMP at various temperatures. Joint disorders increased TT at milder temperatures, at which only 10% of all participants perceived CMP, whereas back disorders did so mainly at lower temperatures, at which 70% were affected. Overweight was associated with a 2 °C lower TT, and physical inactivity with a 1 °C higher TT, and TT increased by 1 °C per 10-year increase in age. The greatest model-estimated difference in median TT between subgroups was 12 °C. Conclusions People suffering from musculoskeletal disorders and those living in the warmer areas of Finland need special advice to protect themselves against the cold. Our study provides preliminary information to support such advice.

Occasionally firefighters need to perform very heavy bouts of work, such as smoke diving or clearing an accident site, which induce significant muscle fatigue. The time span for muscular recovery from such heavy work is not known. The purpose of this study was to evaluate firefighters' force-, neural-, metabolic-, and structural-related recovery after task-specific heavy work in the heat. Fifteen healthy firefighters (14 males and 1 female) performed a 20-min heavy work bout that simulated smoke diving and the clearance of an accident site at 35 °C. After the work, muscular recovery was evaluated by wrist flexion maximal voluntary contraction (MVC), average electromyography during MVC and during 10%MVC, rate of force production, motor response and stretch reflex responses, muscle oxygen consumption and oxygenation level, and wrist flexor muscle pennation angle. Recovery was followed for 4 h. Each of the 12 measured parameters changed significantly (p < 0.05) from those at baseline during the follow-up. Muscle oxygen consumption and the wrist flexor pennation angle remained elevated throughout the follow-up (oxygen consumption baseline, 12.9 ± 1.7 mL O2·min−1·(100 g)−1; 4-h value, 17.5 ± 1.6 mL O2·min−1·(100 g)−1; p < 0.05 and pennation angle baseline, 15.7 ± 0.8°; 4-h value, 17.8 ± 0.8°; p < 0.05). Muscle reoxygenation rate was elevated for up to 2 h (baseline, 2.3 ± 0.4 μmol·L−1·min−1; 2-h value, 3.4 ± 0.4 μmol·L−1·min−1; p < 0.05). The other 9 parameters recovered (were no longer significantly different from baseline) after 20 to 60 min. We concluded that the recovery order in main components of muscle function from fastest to slowest was force, neural, metabolic, and structural.

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how the Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1323). Basic thermal insulation (Icl) of the reported clothing was estimated (ISO 9920). The Icl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the Icl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The Icl of the clothing measured by thermal manikin was 1.9w2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C. Special issue: New development of research on personal protective equipment (PPE) for occupational safety and health

Background: In Finland, children spend a lot of time outdoors in winter. Outdoor recreation in winter has a wide variety of effects on children’s well-being. Although children are a subgroup that is vulnerable to cold exposure, remarkably little research has been done on the subject. Objective: The aim of this study was to describe children’s outdoor recreation, cold exposure and symptoms in winter in Northern Finland. Design: This was a descriptive quantitative study. The participants consisted of 30 children aged 7–8 years who were living in the provinces of Lapland and Northern Ostrobothnia in Finland. Data were collected by using electronic data-logging thermometers fixed on children’s outerwear for a month. The thermometers recorded the environmental temperature every five minutes and from that temperature data, we were able to discern the exact amount and duration of children’s outdoor recreation. In addition, information on the children’s cold symptoms was collected with structured daily entries. Results: Cold weather was not an obstacle to children’s outdoor activities in Finland. However, the duration of outdoor recreation shortened when the outdoor air temperature decreased. There were no significant differences between boys and girls in terms of time spent outdoors. Remarkably, every child reported symptoms associated with cold. Almost half of the children reported experiencing respiratory symptoms and some children also experienced cold pain and numbness. Conclusions: The results of this study illustrate the many and varied effects that cold exposure can have on children’s health and well-being. In order to prevent negative health effects of cold exposure on children, structured prevention strategies are needed: therefore, children’s exposure to cold should be studied more. Future research should also bring out more the positive health effects of outdoor recreation on children’s growth and development.​​​​

The potential impacts of climate change (CC) on Occupational Health and Safety (OHS) have been studied a little in tropical countries, while they received no attention in northern industrialized countries with a temperate climate. This work aimed to establish an overview of the potential links between CC and OHS in those countries and to determine research priorities for Quebec, Canada. A narrative review of the scientific literature (2005-2010) was presented to a working group of international and national experts and stakeholders during a workshop held in 2010. The working group was invited to identify knowledge gaps, and a modified Delphi method helped prioritize research avenues. This process highlighted five categories of hazards that are likely to impact OHS in northern industrialized countries: heat waves/increased temperatures, air pollutants, UV radiation, extreme weather events, vector-borne/zoonotic diseases. These hazards will affect working activities related to natural resources (i.e. agriculture, fishing and forestry) and may influence the socioeconomic context (built environment and green industries), thus indirectly modifying OHS. From this consensus approach, three categories of research were identified: 1) Knowledge acquisition on hazards, target populations and methods of adaptation; 2) Surveillance of diseases/accidents/occupational hazards; and 3) Development of new occupational adaptation strategies.

We present a study that quantifies the effect of cold temperature on smartphone input perform- ance, particularly on tapping tasks. Our results show that smartphone input performance decreases when completing tapping tasks in cold temperatures. We show that colder temperature is associated with lower throughput and less accurate performance when using the phone in both one-handed and two-handed operations. We also demonstrate that colder temperature is related to higher error rate when using the phone in one-handed operation only, but not two-handed. Finally, we identify a number of design recommendations from the literature that can be consid- ered as a countermeasure to poorer smartphone input performance in completing tapping tasks in cold temperature.

The prevalence of heat-related cardiorespiratory symptoms among vulnerable groups is not well known. We therefore estimated the prevalence of heat-related cardiorespiratory symptoms among the Finnish population and their associations with social and individual vulnerability factors. The data came from the National FINRISK 2007 Study, in which 4007 men and women aged 25–74 answered questions on heat-related cardiorespiratory symptoms in the Oulu Cold and Heat Questionnaire 2007. Logistic regression was used to calculate odds ratios (ORs), their 95% confidence intervals (CIs), and model-predicted prevalence figures. The prevalence of heat-related cardiorespiratory symptoms was 12%. It increased with age, from 3% at the age of 25 years to 28% at the age of 75 years. The symptoms were associated with pre-existing lung (OR 3.93; CI 3.01–5.13) and cardiovascular diseases (OR 2.27; 1.78–2.89); being a pensioner (OR 2.91; 1.65–5.28), unemployed (OR 2.82; 1.47–5.48), or working in agriculture (OR 2.27; 1.14–4.46) compared with working in industry; having only basic vs academic education (OR 1.98; 1.31–3.05); being female (OR 1.94; 1.51–2.50); being heavy vs light alcohol consumer (OR 1.89; 1.02–3.32); undertaking hard vs light physical work (OR 1.48;1.06–2.07); and being inactive vs active in leisure time (OR 1.97; 1.39–2.81). The adjusted prevalence of symptoms showed a wide range of variation, from 3 to 61% depending on sex, age, professional field, education, and pre-existing lung and cardiovascular diseases. In conclusion, heat-related cardiorespiratory symptoms are commonly perceived among people with pre-existing lung or cardiovascular disease, agricultural workers, unemployed, pensioners, and people having only basic education. This information is needed for any planning and targeting measures to reduce the burden of summer heat.

The aim of the study was to evaluate the heat stress of Finnish male soldiers (N = 20, age 22.0 ± 2.5 years, body mass 78.8 ± 11.5 kg, and height 180.2 ± 5.6 cm) during their 4-month deployment in a hot environment and to find out the effects on physical performance and body composition. The troops moved from 2.5° C (mean monthly temperature) in Finland to 31.9° C in Chad. During the deployment, temperatures varied between 13.5 and 57.0° C outdoors and in the vehicles and tents. During 1-day recording in the middle of the deployment, skin temperatures were 34-35° C during daytime and maximal core temperature remained mainly below 38.0° C. Body mass decreased (78.4 ± 11.5 kg vs. 75.6 ± 8.6, p = 0.007) during the deployment without changes in fat mass. The sit-up performance increased by 10.9% (46 ± 10 reps·min⁻¹ vs. 51 ± 7 reps·min⁻¹, p < 0.01), and the maximal force production of the leg extensor muscles increased (3,042 ± 614 N vs. 3,277 ± 706 N, p < 0.05) without change in the rate of force development. No changes were observed in the push-ups, repeated squats, maximal grip strength, and running distance during the 12-minute test. In conclusion, the soldiers were able to maintain or improve their physical performance during the deployment despite the heat stress. It is important to encourage soldiers to engage in physical training, especially during a thermally appropriate time of the day or in air-conditioned facilities. Monitoring of local heat stress is also recommended.

The objective of this study was to determine the ability of amlodipine (CAS 88150-42-9, Norvasc) to affect the cold-induced rise of blood pressure and heart rate in normotensive men. Fourteen normotensive men underwent a one-hand cold pressor test (+10 degrees C, 5 min) and a whole-body cold air exposure test (+5 degrees C, 45 min) in a crossover study with and without amlodipine at a seven-day interval. Amlodipine decreased the levels of initial systolic and diastolic blood pressure before both tests, but it had no influence on heart rate. During the cold pressor test, amlodipine lowered the peak diastolic pressure from 96 +/- 10 mmHg (mean +/- SD) to 92 +/- 10 mmHg (p = 0.024). The rise of diastolic blood pressure was 13 +/- 7 mmHg with amlodipine and 16 +/- 8 mmHg without amlodipine (p = 0.138). During the whole-body cold air exposure test, amlodipine decreased the systolic pressure from 135 +/- 2 mmHg to 133 +/- 3 mmHg (p = 0.008) and the diastolic pressure from 88 +/- 2 mmHg to 86 +/- 1 mmHg (p = 0.005). However, the cold-induced rise of blood pressure in whole-body cooling was not affected by amlodipine, because it also decreased the initial values. Amlodipine did not affect the initial or cold-induced changes of heart rate in these tests. In conclusion, in normotensive men amlodipine lowers the peak of diastolic blood pressure in a cold pressor test. In whole-body cold air exposure, amlodipine slightly decreases the levels of both systolic and diastolic pressures, but has no effect on the cold-induced rise of blood pressure. Amlodipine does not prevent the cold-induced physiological responses of blood pressure or heart rate.

The important requirement that COST Action 730 demanded of the physiological model to be used for the Universal Thermal Climate Index (UTCI) was its capability of accurate simulation of human thermophysiological responses across a wide range of relevant environmental conditions, such as conditions corresponding to the selection of all habitable climates and their seasonal changes, and transient conditions representing the temporal variation of outdoor conditions. In the first part of this study, available heat budget/two-node models and multi-node thermophysiological models were evaluated by direct comparison over a wide spectrum of climatic conditions. The UTCI-Fiala model predicted most reliably the average human thermal response, as shown by least deviations from physiologically plausible responses when compared to other models. In the second part of the study, this model was subjected to extensive validation using the results of human subject experiments for a range of relevant (steady-state and transient) environmental conditions. The UTCI-Fiala multi-node model proved its ability to predict adequately the human physiological response for a variety of moderate and extreme conditions represented in the COST 730 database. The mean skin and core temperatures were predicted with average root-mean-square deviations of 1.35 ± 1.00°C and 0.32 ± 0.20°C, respectively.

It is a common practice in Northern countries that children aged about 2 weeks to 2 years take their daytime sleep outdoors in prams in winter. The aim was to evaluate the thermal insulation of clothing of infants sleeping outdoors in winter. Clothing data of infants aged 3.5 months was collected, and sleep duration, skin and microclimate temperatures, humidity inside middle wear, air temperature and velocity of the outdoor environment were recorded during sleep taken outdoors (n = 34) and indoors (n = 33) in families' homes. The insulation of clothing ensembles was measured by using a baby-size thermal manikin, and the values were used for defining clothing insulation of the observed infants. Required clothing insulation for each condition was estimated according to ISO 11079. Clothing insulation did not correlate with ambient air temperature. The observed and required insulation of the study group was equal at about -5 °C, but overdressing existed in warmer and deficiency in thermal insulation in colder temperatures (r (s) 0.739, p0.001). However, even at -5 °C a slow cooling (ca. 0.012 °C/min) of mean skin temperature (T (sk)) was observed. When the difference between observed and required insulation increased, the cooling rate of T (sk) increased linearly (r (s) 0.605, p0.001) and the infants slept for a shorter period (r (s) 0.524, p = 0.001). The results of this study show the difficulty of adjusting systematically the optimal thermal insulation for outdoor sleeping infants during northern winter. Therefore, the necessity for guidelines is obvious. The study provides information for adequate cold protection of infants sleeping in cold conditions.

Aim: The aim of the study is to describe the relationships among thermal environment, skin temperatures and infants’ daytime outdoor sleep duration in northern winter conditions. Methods: This study is a cross-over observational study. Skin temperatures of three-month-old infants were recorded from seven skin sites continuously throughout outdoor (n = 34) and indoor sleep (n = 33) in the families’ homes. The duration of the sleep was observed, and temperature and the air velocity of the environment were recorded. Results: Skin temperatures increased towards the end of indoor sleeping, whereas they decreased during outdoor sleeping. The cooling rate of mean skin temperature (Tsk) increased in lower outdoor temperatures (rs = 0.628, p

Thermal responses and muscular activity in repetitive work were studied in eight women and eight men at 19 degrees C (thermoneutral) and at 4 degrees C (cold). Furthermore, effect of a heating vest was studied at 4 degrees C. Women had lower (p0.05) mean skin temperature compared with men at each thermal condition. Muscular activity (microV) was generally higher in women compared with men, being significantly higher in m. deltoideus (p0.05). Women had lower (p0.01) maximal isometric strength compared with men, which may have influenced the observed higher muscular activity during work in women. However, compared with thermoneutral, working in cold increased (p0.05) muscular activity in the forearm and upper arm extensors only in men. The vest did not significantly counteract the increase in muscular activity. In conclusion, sex differences should be considered when evaluating cold protection and work load reduction in repetitive work in cold environments. Present results indicate that in identical work, sex affects thermal responses and muscular activity during repetitive work in conditions comparable with cooled departments in the food-processing industry. Sex differences should be considered when evaluating cold protection and preventive measures for work load reduction.

This study was designed to find out if local leg cooling affects muscle function and trajectories of the upper limb during repetitive light work as well as capability to maintain dynamic balance. Nine healthy female subjects performed repetitive lifting task with right hand for 60 min while standing in front of a table with six target angles (30 degrees -220 degrees ) and with the legs inside a container with 15 degrees C cold water (Cold condition, C) or without water (Normal condition, N). Muscle temperature of the medial aspect of the gastrocnemius, rectal, and skin temperatures were measured continuously. The trajectories of the right upper limb were recorded with a 3D motion analysis system. Muscular strain (averaged EMG, a-EMG) and EMG gaps in eight muscles of the right upper limb were measured. End point excursion depicting the ability to maintain dynamic balance was measured before and after each experiment. Leg cooling decreased significantly (P < 0.05) the muscle and the mean skin temperature in C compared with N (6.7 and 2.2 degrees C, respectively). No marked changes in the trajectories or EMG activity were observed between the different environmental conditions. The end point excursion was significantly (P < 0.05) reduced in C compared with N and a positive correlation between excursion and muscle temperature was found at the end of the working period in C. In conclusion, local leg cooling did not affect upper limb muscle function or trajectories, but ability to maintain dynamic balance was reduced.

Introduction The associations between melatonin and thyroid hormones and changes in mood and cognitive performance caused by exposure to cold and darkness were examined in 12 circumpolar residents during winter and summer. Methods Each participant was exposed to three different experimental conditions in random order: 1) 22 degrees C and bright light; 2) 10 degrees C and bright light; and 3) 10 degrees C and dim light. The duration of each exposure was 24 h. Results Increased serum melatonin and thyrotropin were associated with decreased rectal temperature (r = -0.446 - -0.580) and increased mean skin temperature (r = 0.204-0.519). Higher serum melatonin was associated with increased vigor (r = 0.330) and decreased accuracy on simple cognitive tasks (r = -0.332 - -0.430). Increased serum free triiodothyronine (fT3) was associated with decreased negative mood scores (r = -0.365 - -0.483), decreased response time (RT) on the simple reaction time (SRT) task (r = -0.606), and decreased accuracy on the addition/subtraction task (r = -0.372). Higher serum free thyroxine was associated with decreased fatigue and anger (r = -0.409 - -0.522). Increased serum thyrotropin was associated with decreased accuracy and RT on the SRT task and decreased RT on the grammatical reasoning task (r = -0.315 - -0.415). Conclusions Associations between serum melatonin and thyroid hormones with mood were consistent with the psychological changes associated with the polar triiodothyronine syndrome. Also, serum melatonin and thyrotropin were associated with impaired and fT3 with improved cognitive performance, supporting the decrements in cognitive performance associated with the polar triiodothyronine syndrome.

The study examined the impact of chemical protective (CP) clothing on the performance of lifesaving tasks in thermoneutral and cold conditions. Eleven males performed pre-exercise followed by lifesaving tasks wearing either field combat uniform at 21 degrees C (U) or CP clothing at 21 degrees C (CPN) and -5 degrees C (CPC). The tasks were ventilating a doll (VA) and connecting an intravenous line (IV). Mean skin temperature was significantly higher for CPN compared to U and CPC during pre-exercise, VA and IV. Changes in blood pressure were significantly greater with CP clothing than without during VA and IV. The number of breaths per min (in VA) and time needed for IV increased by 19% (p0.05) and 18%, respectively, for CPN compared to U. Due to the cold, the additional increment was 5% and 17%, respectively, for CPC. Wearing of CP clothing in thermoneutral or in cold conditions may not prevent but, especially in the cold, significantly impede the performance of basic medical tasks. The findings of this study showed that performing medical tasks while wearing nuclear, biological and chemical protective clothing is impaired due to significant changes in physiological strain. This suggests that realistic training in local conditions as well as in cold conditions is needed to realise the restrictions due to protective clothing.

The objective of this study was to explain the contribution of lower extremity muscle activity to gait kinetic and kinematic adaptations for maintaining gait dynamic balance when walking on an inclined icy surface and the biomechanical mechanisms used to counteract slip risk. A two-way factorial experimental design was applied. The two independent variables were the walkway surface (ice and treadmill) and the walkway inclination (0 masculine, 6 masculine, 8 masculine). The dependent variable was the amplitude of the surface EMG of four right lower extremity muscles (tibialis anterior TA, gastrocnemius lateralis GL, rectus femoris RF, and biceps femoris BF). Twelve healthy subjects (7 males and 5 females) participated in the walking trials. A two-way ANOVA analysis showed that on the icy surface in the heel contact phase, EMG amplitudes significantly decreased in TA and RF compared to those for the treadmill surface. In the mid-stance phase, the GL muscle activity significantly decreased on ice compared to treadmill and all four muscle activities increased significantly with the inclination. During the toe off phase, GL and RF activities increased with the inclination. The mechanisms identified may be applied to develop intervention, rehabilitation and training techniques, and to improve performance in human locomotion, such as for winter sports.

The present study was designed to find out if cooling and/or clothing affect the vertical trajectories and muscle function of the upper arm during repetitive light work. Twelve female subjects performed a one-handed lifting task for 60 min while standing in front of a table with six target angles (30 degrees to 220 degrees ). The experiment was carried out in a climatic chamber in three different conditions: at 10 degrees C (C), at 25 degrees C (TN), and at 10 degrees C dressed in cold-protective clothing (C(p)). Skin and rectal temperatures were measured continuously. The vertical trajectories of the head, shoulder, elbow, and wrist on the right side of the body were recorded. Muscular strain (averaged EMG, a-EMG) and EMG gaps in eight muscles on the right upper arm were measured. The variation of the vertical trajectory amplitude of the upper arm measured from the elbow was significantly higher (at 200 degrees ) both at C and C(p) (50 and 25% respectively) and in shoulder (at 220 degrees angle) at C (33%) compared with TN (P < 0.05). Both C and C(p) increased a-EMG and reduced the number and duration of EMG gaps significantly in all muscles studied. In conclusion, in repetitive tasks the high mean vertical trajectory and changes in the amplitude of the trajectory of the upper arm at C and C(p) compared with TN were associated with increased muscular strain and reduced number of EMG gaps (more continuous activation of given muscle fibers). The changes in trajectories may serve as indicator of a risk for local muscle fatigue.

1. The study evaluated the effects of exposure to cold air (10 °C) on thermal responses, muscle performance and dexterity of muscular subjects and their matched lean counterparts. 2. No differences in rectal and skin temperatures or in the rate of cooling were observed between the groups. In muscularity group (MG), maximal wrist flexion force was higher but ball velocity during throwing and jump height tended to be lower. Dexterity did not differ between the groups. The average decrease in performance (including all tests) in MG was 12.3±5.1% and in lean group it was 9.3±4.1%. 3. It is concluded that muscularity does not protect against cooling nor does it maintain muscle performance capacity or dexterity as compared to matched lean counterparts.

Working in open-pit mines in the Barents region requires protection against cold, occasionally extreme temperatures and high wind speed. Employers are required to provide outer cold protective clothing for workers in outdoor tasks. Some companies also offer inner or middle clothing layers for voluntary use. However, workers use their own selection of winter garments underneath the outer clothing. This study aimed to evaluate the selection criteria of winter clothing of open-pit miners and its thermal protection at work.

The purpose of this study is to perform a multiparametric analysis on the environmental factors, the physiological stress reactions in the body, the measured alertness, and the subjective symptoms during simulated office work. Volunteer male subjects were monitored during three 4-hr work meetings in an office room, both in a ventilated and a non-ventilated environment. The environmental parameters measured included CO(2), temperature, and relative humidity. The physiological test battery consisted of measuring autonomic nervous system functions, salivary stress hormones, blood's CO(2)- content and oxygen saturation, skin temperatures, thermal sensations, vigilance, and sleepiness. The study shows that we can see physiological changes caused by high CO(2) concentration. The findings support the view that low or moderate level increases in concentration of CO(2) in indoor air might cause elevation in the blood's transcutaneously assessed CO(2). The observed findings are higher CO(2) concentrations in tissues, changes in heart rate variation, and an increase of peripheral blood circulation during exposure to elevated CO(2) concentration. The subjective parameters and symptoms support the physiological findings. This study shows that a high concentration of CO(2) in indoor air seem to be one parameter causing physiological effects, which can decrease the facility user's functional ability. The correct amount of ventilation with relation to the number of people using the facility, functional air distribution, and regular breaks can counteract the decrease in functional ability. The findings of the study suggest that merely increasing ventilation is not necessarily a rational solution from a technical-economical viewpoint. Instead or in addition, more comprehensive, anthropocentric planning of space is needed as well as instructions and new kinds of reference values for the design and realization of office environments.

Severe hypothermia has been shown to influence the levels of catecholamines and thrombomodulin, an endothelial protein essentially involved in the regulation of haemostasis and inflammation. A link between thrombomodulin and catecholamines during cold exposure has also been previously suggested. The aim of this study was to assess the influence of short-term cold exposure without hypothermia on catecholamines and the circulating and urinary thrombomodulin levels. Seven healthy male subjects were immersed in cold water (+10°C) for 10 minutes followed by a 20-minute immersion in +28°C water. Warm water immersion was performed separately for each subject (+30°C for 30 minutes). Thrombomodulin and catecholamine concentrations were measured from pre- and post-immersion (up to 23 hours) samples. In urine, the thrombomodulin level correlated strongly with adrenaline (ρ = 0.806) and noradrenaline (ρ = 0.760) levels. There were no significant differences in thrombomodulin levels between immersion temperatures. Post-immersion urinary thrombomodulin levels were significantly lower than the pre-immersion level at both immersion temperatures. Median concentrations of plasma noradrenaline and urinary adrenaline were higher after exposure to +10°C than to +30°C. Thus, further evidence of the association between thrombomodulin and catecholamines was gained in a physiologically relevant setting in humans. Additionally, it is evident that a short-term cold exposure was not able to elicit changes in the thrombomodulin levels in a follow-up period of up to 23 hours. These findings provide further understanding of the physiological responses to cold during immersion, and of the potential influence of stress on haemostatic and inflammatory responses.

The purpose of this cross-sectional study was to investigate muscular strain and thermal responses of female workers during meatpacking work in cooled departments in a large meat processing factory. The measurements were performed among 18 healthy women during their normal work tasks at a temperature of 4–10 °C. Muscular strain in upper extremities and the shoulder region was measured by continuous electromyography (EMG). Relative muscular strain was calculated from EMG activity during work in relation to maximal EMG activity measured during maximal voluntary contraction. Skin and rectal temperatures were measured continuously. The results showed that muscular strain was the highest in wrist extensor muscles (m. extensor digitorum), being 16–18% of the maximal EMG activity (% MEMG), while the respective values in wrist flexor muscles (m. flexor carpi radialis) were 8–12% MEMG and in the shoulder region, 6–7% MEMG in the medial part of m. deltoideus and 8–14% MEMG in the descending part of m. trapezius. Working in cooled departments decreased skin temperatures most in the shoulder region, fingers and lower extremities. However, the association between skin temperatures and muscular strain was not statistically significant. It can be concluded that muscular strain was mainly related to the intensity of repetitive work movements. Relevance to industry The results suggests that in industries where repetitive manual work and cold are combined, preventive measures such as improvements in cold protective clothing and ergonomic interventions in repetitive work tasks might be considered to prevent cooling and to reduce upper extremity muscular strain.

Objectives This study attempted to determine whether repetitive work in the cold affects the number of electromyographic (EMG) gaps and whether cold-induced deterioration in neuromuscular function can be restored by altering work intensity. Methods During 2 hours of simulated sausage packing, the occurrence of EMG gaps was studied in eight upper-extremity muscles at 19°C and 4°C. The additional effect of continuous, light repetitive work [wrist flexion–extension 10% of the maximal voluntary contraction (MVC), Cwork] and intermittently increased workload (10% or 30% MVC) (Iwork) on forearm muscle EMG gaps, the median frequency of the EMG spectrum, EMG activity, and muscle fatigue (as indicated by changes in the MVC of wrist flexion) at 4°C was studied. Results During work simulation, the mean skin temperature decreased from 33.3 (SD 0.1)°C to 30.6 (SD 0.2)°C (P

The aim of this study was to examine whether urinary melatonin, rather than urinary 6-sulfatoxymelatonin (aMT6s), can be used as an indicator of diurnally and seasonally changing melatonin secretion. The subjects (n=15) spent three separate 24-hr periods in a climatic chamber during winter (n=7) and summer (n=8). Blood and urine samples were obtained during each period at 2- to 5-hr intervals. Serum melatonin and urinary melatonin and aMT6s were assayed by radioimmunoassay. The serum melatonin levels increased nearly 10-fold from low daytime to high nocturnal values. The mean nocturnal increase of urinary melatonin was 1.7-fold and that of urinary aMT6s was 4.6-fold. Both urinary melatonin and aMT6s correlated significantly with area under the curve melatonin in serum during the night, during the day and throughout the entire 24-hr observation period in all cases. The ratio between urinary melatonin and aMT6s excretion showed significant diurnal variation, being ninefold higher at 16:00 hr than at 07:00 or at 09:00 hr. The ninefold decrease in the urinary melatonin/aMT6s excretion ratio between the evening and the morning may reflect increased liver metabolism of melatonin during the night. Both urinary melatonin and aMT6s are good indicators of melatonin secretion, but the variation is significantly smaller for the former molecule.

In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.

Six mildly hypertensive subjects were exposed three times to −15 °C (wind 3.5 m/s) for 15 min. After an initial exposure for familiarisation, second and third exposures were arranged in a random double blind, crossover fashion after a week's ingestion of hydrochlorothiazide or placebo. Cold decreased skin temperatures, but not rectal temperature. Blood pressure increased 30/20 mmHg and heart rate decreased 12 beats/min by cold. Blood pressure seems to react in 3 min to changes in ambient temperature. The skin temperatures of uncovered body parts were apparently responsible for that. Hydrochlorothiazide did not affect either cardiovascular or thermal responses in cold.

To determine whether urban circumpolar residents show seasonal acclimatisation to cold, thermoregulatory responses and thermal perception during cold exposure were examined in young men during January-March (n=7) and August-September (n=8). Subjects were exposed for 24 h to 22 and to 10 degrees C. Rectal (T(rect)) and skin temperatures were measured throughout the exposure. Oxygen consumption (VO(2)), finger skin blood flow (Q(f)), shivering and cold (CDT) and warm detection thresholds (WDT) were assessed four times during the exposure. Ratings of thermal sensations, comfort and tolerance were recorded using subjective judgement scales at 1-h intervals. During winter, subjects had a significantly higher mean skin temperature at both 22 and 10 degrees C compared with summer. However, skin temperatures decreased more at 10 degrees C in winter and remained higher only in the trunk. Finger skin temperature was higher at 22 degrees C, but lower at 10 degrees C in the winter suggesting an enhanced cold-induced vasoconstriction. Similarly, Q(f) decreased more in winter. The cold detection threshold of the hand was shifted to a lower level in the cold, and more substantially in the winter, which was related to lower skin temperatures in winter. Thermal sensations showed only slight seasonal variation. The observed seasonal differences in thermal responses suggest increased preservation of heat especially in the peripheral areas in winter. Blunted vasomotor and skin temperature responses, which are typical for habituation to cold, were not observed in winter. Instead, the responses in winter resemble aggravated reactions of non-cold acclimatised subjects.

1. Skin and rectal temperatures were recorded continuously in 70 measurements during typical tasks of infantry and artillery training at 0 to −29 °C. The duration of the measurements varied from 55 min to 9.5 h. 2. The distribution of finger skin temperatures was quite similar at ambient temperature ranges 0 to −10 °C and −10 to −20 °C, while at −20 to −30 °C the finger temperatures were clearly lower. 3. At different ambient temperature ranges, 20–69% of finger temperatures were low enough to cause cold thermal sensations. 4. Sensation of cold was experienced at a finger temperature of 11.6±3.7 °C (mean±SD).

This study aimed to measure cardiorespiratory fitness of about 9000 males and females at age 31, to produce the reference values and relate them to the level of physical activity and body mass index (BMI). Study population was the Northern Finland birth cohort of 1966. At age 31, 8786 persons responded to a postal inquiry including questions about physical activity and 5497 of them also performed a step test. A sample of 123 persons performed a maximal exercise test with direct measurement of peak oxygen uptake (VO(2peak)). This was done to develop VO(2peak) prediction models on the basis of heart rate after a step test, BMI and frequency of brisk physical activity. These models were used to calculate VO(2peak) for the whole study population. Mean VO(2peak) +/- standard deviation was 43.0 +/- 4.6 ml.kg(-1).min(-1) in 4071 males and 34.3 +/- 4.3 ml.kg(-1).min(-1) in 4367 females. A graded dose-response relationship was observed in males and females between the frequency of participation in brisk exercise and VO(2peak). Similar dose-response relationship was also observed in overweight and obese persons, although the level of VO(2peak) was lower in persons with increased BMI. At age 31, very low levels of VO(2peak) seemed to be associated with a combination of infrequent participation in brisk exercise and increased BMI. These reference values can be used in the interpretation of fitness test results and in physical activity counselling.

Background Physical inactivity is related to an increased risk of certain chronic diseases. The aim here was to evaluate how physical activity and social status in adolescence are associated with physical inactivity in adulthood. Methods The sample comprised 3664 males and 4130 females who answered questions on physical activity and social status at 14 and 31 years of age in follow-up surveys of the Northern Finland birth cohort of 1966. Associations between explanatory factors and physical inactivity in adulthood were analyzed using multivariable logistic regression. Results Infrequent participation in sports after school hours at 14 years of age and, in males, additionally a low grade in school sports, was associated with physical inactivity at the age of 31 years, independent of social circumstances in adulthood. Low social class of the childhood family was associated with physical inactivity in adolescence but not with inactivity at 31 years of age. Poor school achievement in adolescence was associated with adult inactivity independent of adolescent physical activity. Conclusion Infrequent participation in sports, a low grade in school sports, and poor school achievements in adolescence were associated with physical inactivity in adulthood. Participation in sports is to be strongly supported among all adolescents because of its long-term beneficial effects on adult health through its tendency to reduce the probability of adult inactivity.

The effects of low to moderate wind speeds on face temperature, thermal and pain sensations while subjects walked on a treadmill during cold exposure were studied in eight healthy men. The purpose of the study was to evaluate further the risk of frostbite at different activity levels. The walking speed was 2.8 km h(-1) and two inclination levels were used, 0 degrees and 6 degrees. The subjects were exposed to -10 degrees C and 0, 1 or 5 m s(-1) wind for 60 min dressed in cold-protective clothing with only the face unprotected. Results from previous experiments with the same subjects standing for 30 min were included in the analysis of the data. Each individual was exposed to all combinations of air velocity and activity level. The exposure to -10 degrees C and the highest wind speed used would carry no risk of frostbite according to the wind chill index. Cold lowered the skin temperature of the face significantly and wind further increased skin cooling. The activity level did not affect forehead and cheek temperatures, but the average nose skin temperature was higher and pain sensations were reduced at a higher work rate. The predicted risk of frostbite in the nose, based on average responses, would thus be less at a higher work rate. However, the results indicate that exercise does not necessarily protect all individuals from frostbite at moderate air speeds, since the nose skin temperature of 25% of the subjects dropped to 0 degrees C at 5 m s(-1) during both standing and walking. Thus the potential individual risk of frostbite in the nose is similar during light exercise and standing. Moreover, the risk of frostbite seems to be underestimated by the wind chill index under the conditions tested in this study.

This study compared the effect of repetitive work in thermoneutral and cold conditions on forearm muscle electromyogram (EMG) and fatigue. We hypothesize that cold and repetitive work together cause higher EMG activity and fatigue than repetitive work only, thus creating a higher risk for overuse injuries. Eight men performed six 20-min work bouts at 25°C (W-25) and at 5°C while exposed to systemic (C-5) and local cooling (LC-5). The work was wrist flexion-extension exercise at 10% maximal voluntary contraction. The EMG activity of the forearm flexors and extensors was higher during C-5 (31 and 30%, respectively) and LC-5 (25 and 28%, respectively) than during W-25 ( P < 0.05). On the basis of fatigue index (calculated from changes in maximal flexor force and flexor EMG activity), the fatigue in the forearm flexors at the end of W-25 was 15%. The corresponding values at the end of C-5 and LC-5 were 37% ( P < 0.05 in relation to W-25) and 20%, respectively. Thus repetitive work in the cold causes higher EMG activity and fatigue than repetitive work in thermoneutral conditions.

This field study evaluated the level of muscular, cardiorespiratory and thermal strain of mast and pole workers. We measured the muscular strain using electromyography (EMG), expressed as a percentage in relation to maximal EMG activity (%MEMG). Oxygen consumption (VO2) was indirectly estimated from HR measured during work and expressed as a percentage of maximum VO2 (%VO2max). Skin and deep body temperatures were measured to quantify thermal strain. The highest average muscular strain was found in the wrist flexor (24 ± 1.5%MEMG) and extensor (21 ± 1.0%MEMG) muscles, exceeding the recommendation of 14%MEMG. Average cardiorespiratory strain was 48 ± 3%VO2max. Nearly half (40%) of the participants exceeded the recommended 50%VO2max level. The core body temperature varied between 36.8°C and 37.6°C and mean skin temperature between 28.6°C and 33.4°C indicating possible occasional superficial cooling. Both muscular and cardiorespiratory strain may pose a risk of local and systemic overloading and thus reduced work efficiency. Thermal strain remained at a tolerable level.

Exercise and shivering rely on different metabolic pathways and consequently, fuel selection. The present study examined the effects of a pre-exercise low-intensity shivering protocol on fuel selection during submaximal exercise in a cold environment. Nine male subjects exercised 4 times for 60 min at 50% (LOW) or 70% (MOD) of their peak oxygen consumption on a motorized treadmill in a climatic chamber set at 0 °C with (SHIV) and without (CON) a pre-exercise cooling protocol, inducing low-intensity shivering. Thermal, cardiorespiratory and metabolic responses were measured every 15 min whereas blood samples were collected every 30 min to assess serum nonesterified fatty acids (NEFA), glycerol, glucose, β-hydroxybutyrate (BHB) and plasma catecholamine concentrations. Rectal and skin temperatures were lower in the SHIV condition, within LOW and MOD conditions, during the first 45 min of exercise. Norepinephrine (NE) concentration was greater in SHIV vs. CON within LOW (1.39 ± 0.17 vs. 0.98 ± 0.17 ng·mL−1) and MOD (1.50 ± 0.20 vs. 1.01 ± 0.09 ng·mL−1), whereas NEFA, glycerol and BHB were greater in SHIV vs. CON (1060 ± 49 vs. 898 ± 78 μmol·L−1; 0.27 ± 0.02 vs. 0.22 ± 0.03 mmol·L−1; 0.39 ± 0.06 vs. 0.27 ± 0.04 mmol·L−1, respectively) within MOD only. No changes were observed in fat or carbohydrate oxidation between SHIV and CON during exercise. Despite increases in NE, NEFA, glycerol and BHB from pre-exercise low-intensity shivering, fuel selection during short-term submaximal exercise in the cold was unaltered.