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• The integrated socio-ecological-economic index (SEEI) was used to assess heat health risk at the neighborhood scale. • The spatial distribution of SEEI in Shanghai showed urban being 2–3 times higher than in the suburbs. • The SEEI in Shanghai peaked in 2010 and declined by 2020, with high-risk neighborhoods dropping from seven to none. • The heat-related mortality indicators showed significant correlations with the SEEI. Extreme heat events caused by climate change and rapid urbanization are major environmental issues affecting the health of urban populations, especially in metropolitan areas. However, few studies have employed a systematic risk assessment model to delineate heat health risk (HHR) in rapidly urbanizing metropolitan areas at a finer resolution, and rare studies have used epidemiological approaches for validation, as mortality is typically considered the most crucial indicator for assessing health impact. Here, a novel integrated socio-ecological-economic index (SEEI) was used to analyze the spatial distribution and evolution of HHR with a neighborhood resolution in Shanghai from 2000 to 2020, and four heat-related mortality indicators were applied to validate. The results showed that (1) the spatial distribution of the SEEI in Shanghai exhibited significant differences between urban and suburban areas, with the main urban areas having an average SEEI 2–3 times higher than suburban areas. (2) Overall, the SEEI peaked in 2010 and declined in 2020, with very high-risk neighborhoods decreasing from seven in 2000 to none in 2020. However, there was a slight trend towards a wider range of moderate-risk neighborhoods. (3) The heat-related mortality indicators exhibited significant correlations with SEEI, demonstrating the reliability of the SEEI as also confirmed by sensitivity analysis. The SEEI used in this study can provide a basis for decision-making for Shanghai as well as similar metropolitan areas to prevent extreme heat events. [ABSTRACT FROM AUTHOR]

Temperature-related mortality mostly affects older people and is attributable to a combination of factors. We focussed on a key non-temperature factor – rising longevity – and aimed to quantify its reciprocal relation with temperature-related mortality risk in Spain over 1980–2018. We obtained average annual temperature-attributable deaths among people aged 65y+, by sex and age group, for different temperature ranges (extreme cold, moderate cold, moderate heat, and extreme heat), from a previous study. Combining this with population and mortality data as well as life table information, we used: (i) a counterfactual approach to assess the contribution of rising longevity to changes in the absolute risk of temperature-related mortality, and (ii) decomposition to assess the contribution of changes in temperature-related mortality to changes in longevity and its variation (lifespan inequality). Rising longevity led to considerable declines in the absolute risk of temperature-related mortality in females and males across the entire temperature range. For extreme heat, it accounted for about a 30% decrease in absolute risk (half of the total decrease over the study period). For moderate and extreme cold, it accounted for about a 20% fall in absolute risk (a quarter of the total fall). In the opposite direction, changing patterns of temperature-related deaths contributed to higher life expectancy (accounting for > 20% of the total rise in both females and males) but also higher lifespan inequality amongst older people. Most of the influence (about 80%) was via moderate cold, but declines in risk at both moderate and extreme heat led to small rises in life expectancy. Our study points to the benefits of adopting risk-reduction strategies that aim, not only at modifying hazards and reducing exposure, but that also address socially-generated vulnerability among older people. This includes ensuring that lifespans lengthen primarily through increases in years lived in good health. [ABSTRACT FROM AUTHOR]

Heat-related mortality is increasing as the result of climate change, extreme heat events and higher ambient temperature because of urban heat island (UHI) phenomenon. We coupled the Weather Research and Forecasting model (WRFV3.6.1) with a multi-layer of the Urban Canopy Model (ML-UCM) to investigate the effects of UHI intensity during the 2005 and 2011 heat wave periods in Greater Montreal Area (GMA), Canada. Each day of simulation is categorized into an air mass type using the Spatial Synoptic Classification. Using the non-accidental mortality data during summer period, the number of deaths above the expected mean anomalous daily mortality is calculated for each air mass classification. Results indicate that moist tropical plus and dry tropical weather have the highest rank in heat-related death. We assessed the effects of increasing surface reflectivity (ISR) on four meteorological parameters: 2-m air temperature, 10-m wind speed, 2-m relative humidity, dew point temperature, and four heat stress indices: National Weather Service – Heat Index, Apparent Temperature, Canadian Humid Index, and Discomfort Index (DI). ISR decreased air temperature by 0.6 °C, increased relative humidity by 2%, increased dew point temperature by 0.4 °C. The DI improved by 3% and heat-related mortality decreased by nearly 3.2% during heat wave periods in GMA. [ABSTRACT FROM AUTHOR]

Background Excessive summer heat is a serious environmental health problem in several European cities. Heat-related mortality and morbidity is likely to increase under climate change scenarios without adequate prevention based on locally relevant evidence. Methods We modelled the urban climate of Antwerp for the summer season during the period 1986–2015, and projected summer daily temperatures for two periods, one in the near (2026–2045) and one in the far future (2081–2100), under the Representative Concentration Pathway (RCP) 8.5. We then analysed the relationship between temperature and mortality, as well as with hospital admissions for the period 2009–2013, and estimated the projected mortality in the near future and far future periods under changing climate and population, assuming alternatively no acclimatization and acclimatization based on a constant threshold percentile temperature. Results During the sample period 2009–2013 we observed an increase in daily mortality from a maximum daily temperature of 26 °C, or the 89th percentile of the maximum daily temperature series. The annual average heat-related mortality in this period was 13.4 persons (95% CI: 3.8–23.4). No effect of heat was observed in the case of hospital admissions due to cardiorespiratory causes. Under a no acclimatization scenario, annual average heat-related mortality is multiplied by a factor of 1.7 in the near future (24.1 deaths/year CI 95%: 6.78–41.94) and by a factor of 4.5 in the far future (60.38 deaths/year CI 95%: 17.00–105.11). Under a heat acclimatization scenario, mortality does not increase significantly in the near or in the far future. Conclusion These results highlight the importance of a long-term perspective in the public health prevention of heat exposure, particularly in the context of a changing climate, and the calibration of existing prevention activities in light of locally relevant evidence. [ABSTRACT FROM AUTHOR]

Heat-related mortality is of growing concern for cities faced with the combined effects of increasing heat-wave frequency and intensity and stronger urban heat islands (UHI). In cities around the world, high air temperatures have been found to have strong repercussions in terms of heat-related mortality for populations aged 65 years and older, especially nighttime temperatures. In response, many measures have been proposed to counteract the effects of UHI such as cool roofs and materials or urban greening. While these approaches are promising and are rightfully explored, behavioral adaptation measures have not received as much attention. Given the importance of nighttime temperatures on heat-wave mortality and the importance of sleep quality for individuals to recover from intense daytime heat exposure, adapting sleeping habits to reduce sleep time exposure to intense heat may help reduce the health impacts of heat-waves. In this paper, outdoor and indoor temperature measurements conducted over the summer of 2015 in the bedrooms of two apartments in Paris, France are analyzed. The potential for this kind of behavioral adaptation to reduce occupant exposure to high sleep time temperatures is quantified and discussed. The policy implications of our findings and their practicality are also mentioned. [ABSTRACT FROM AUTHOR]

Background Heat-waves have a substantial public health burden. Understanding spatial heterogeneity at a fine spatial scale in relation to heat and related mortality is central to target interventions towards vulnerable communities. Objectives To determine the spatial variability of heat-wave-related mortality risk among elderly in Paris, France at the census block level. We also aimed to assess area-level social and environmental determinants of high mortality risk within Paris. Methods We used daily mortality data from 2004 to 2009 among people aged > 65 at the French census block level within Paris. We used two heat wave days' definitions that were compared to non-heat wave days. A Bernoulli cluster analysis method was applied to identify high risk clusters of mortality during heat waves. We performed random effects meta-regression analyses to investigate factors associated with the magnitude of the mortality risk. Results The spatial approach revealed a spatial aggregation of death cases during heat wave days. We found that small scale chronic PM 10 exposure was associated with a 0.02 (95% CI: 0.001; 0.045) increase of the risk of dying during a heat wave episode. We also found a positive association with the percentage of foreigners and the percentage of labor force, while the proportion of elderly people living in the neighborhood was negatively associated. We also found that green space density had a protective effect and inversely that the density of constructed feature increased the risk of dying during a heat wave episode. Conclusion We showed that a spatial variation in terms of heat-related vulnerability exists within Paris and that it can be explained by some contextual factors. This study can be useful for designing interventions targeting more vulnerable areas and reduce the burden of heat waves. [ABSTRACT FROM AUTHOR]

Cities are developing innovative strategies to combat climate change but there remains little knowledge of the winners and losers from climate-adaptive land use planning and design. We examine the distribution of health benefits associated with land use policies designed to increase vegetation and surface reflectivity in three US metropolitan areas: Atlanta, GA, Philadelphia, PA, and Phoenix, AZ. Projections of population and land cover at the census tract scale were combined with climate models for the year 2050 at 4 km × 4 km resolution to produce future summer temperatures which were input into a comparative risk assessment framework for the temperature-mortality relationship. The findings suggest disparities in the effectiveness of urban heat management strategies by age, income, and race. We conclude that, to be most protective of human health, urban heat management must prioritize areas of greatest population vulnerability. [ABSTRACT FROM AUTHOR]

The health impacts of exposure to summertime heat are a significant problem in New York City (NYC) and for many cities and are expected to increase with a warming climate. Most studies on heat-related mortality have examined risk factors at the municipal or regional scale and may have missed the intra-urban variation of vulnerability that might inform prevention strategies. We evaluated whether place-based characteristics (socioeconomic/demographic and health factors, as well as the built and biophysical environment) may be associated with greater risk of heat-related mortality for seniors during heat events in NYC. As a measure of relative vulnerability to heat, we used the natural cause mortality rate ratio among those aged 65 and over (MRR65+), comparing extremely hot days (maximum heat index 100°F+) to all warm season days, across 1997-2006 for NYC's 59 Community Districts and 42 United Hospital Fund neighborhoods. Significant positive associations were found between the MRR65+ and neighborhood-level characteristics: poverty, poor housing conditions, lower rates of access to air-conditioning, impervious land cover, surface temperatures aggregated to the area-level, and seniors' hypertension. Percent Black/African American and household poverty were strong negative predictors of seniors' air conditioning access in multivariate regression analysis. [ABSTRACT FROM AUTHOR]

Maricopa County, Arizona, anchor to the fastest growing megapolitan area in the United States, is located in a hot desert climate where extreme temperatures are associated with elevated risk of mortality. Continued urbanization in the region will impact atmospheric temperatures and, as a result, potentially affect human health. We aimed to quantify the number of excess deaths attributable to heat in Maricopa County based on three future urbanization and adaptation scenarios and multiple exposure variables. Two scenarios (low and high growth projections) represent the maximum possible uncertainty range associated with urbanization in central Arizona, and a third represents the adaptation of high-albedo cool roof technology. Using a Poisson regression model, we related temperature to mortality using data spanning 1983–2007. Regional climate model simulations based on 2050-projected urbanization scenarios for Maricopa County generated distributions of temperature change, and from these predicted changes future excess heat-related mortality was estimated. Subject to urbanization scenario and exposure variable utilized, projections of heat-related mortality ranged from a decrease of 46 deaths per year (− 95%) to an increase of 339 deaths per year (+ 359%). Projections based on minimum temperature showed the greatest increase for all expansion and adaptation scenarios and were substantially higher than those for daily mean temperature. Projections based on maximum temperature were largely associated with declining mortality. Low-growth and adaptation scenarios led to the smallest increase in predicted heat-related mortality based on mean temperature projections. Use of only one exposure variable to project future heat-related deaths may therefore be misrepresentative in terms of direction of change and magnitude of effects. Because urbanization-induced impacts can vary across the diurnal cycle, projections of heat-related health outcomes that do not consider place-based, time-varying urban heat island effects are neglecting essential elements for policy relevant decision-making. [ABSTRACT FROM AUTHOR]

Abstract: Temperature–mortality analyses are challenging in rural and remote communities with small populations, but this information is needed for climate change and emergency planning. The geographic health areas of British Columbia, Canada were aggregated into four ecoregions delineated by microclimatic conditions. Time series models were used to estimate the effect of maximum apparent temperature on daily non-traumatic mortality. The population of the coldest ecoregion was most sensitive to hot weather, while the population of the hottest ecoregion was least sensitive. The effects were consistently strongest in decedents aged less than 75 years. A province-wide total of 815 deaths was attributed to hot weather over the 25-year study period, with 735 deaths in the most populous ecoregion. The framework described could be adapted to other climatically variable regions with urban, rural, and remote populations. [Copyright &y& Elsevier]

Abstract: This study assesses heat-related mortality in Massachusetts during the months of May through September from 1990 to 2008. Daily maximum apparent temperature was interpolated across space via kriging, and aggregated to 29 municipality groups (MGs), a spatial unit composed of municipalities that was designed to have minimal variation in population. Death certificate data were analyzed to determine the spatial distribution of excess mortality on days that exceeded the 85th, 90th, and 95th percentiles of apparent temperature. We find that the average statewide mortality anomalies were 5.11, 6.26, and 7.26 deaths on days exceeding the 85th, 90th, and 95th percentiles of apparent temperature respectively. A linear stepwise regression showed that percent African–American population and percent elderly population (those above the age of 65) were positively associated with an MG’s mortality anomaly on days exceeding the 85th percentile of apparent temperature (p < 0.05). In spite of the urban heat island effect, our measure of urbanization was not associated with higher rates of heat-related mortality. [Copyright &y& Elsevier]

Abstract: We compare heat-related mortality impacts for three European cities, London, Lisbon and Budapest, under five climate change policies representing different dates at which carbon dioxide (CO2) emissions peak, rates at which emissions decline, and emissions floors, and compare them with a non-mitigation business-as-usual emissions scenario, for three time periods, the 2030s, 2050s and 2080s. Under an SRES A1B business-as-usual emissions scenario and using climate projections from 21 GCMs, heat-related mortality rates (per 100,000 of the population) attributable to climate change in the 2080s are simulated to be in the range 2-6 for London, 4-50 for Lisbon and 10-24 for Budapest. Whilst the policy scenarios serve to reduce the number of heat-related deaths attributable to climate change, by up to 70% of the A1B impacts under an aggressive mitigation scenario that gives a 50% chance of avoiding a 2°C global-mean temperature rise from pre-industrial times, they do not eradicate the effects of climate change on heat-related mortality. The magnitude of avoided impacts is minor in the early 21st century but increases towards the end of the century. Importantly, the magnitude of avoided impacts is more sensitive to the year at which emissions are reduced than to the rate at which emissions are reduced. [Copyright &y& Elsevier]

Abstract: Mortality–temperature relationships in small regional towns in Victoria, Australia, were used to ascertain whether the effects of high ambient temperatures documented in the literature for major population centres in Europe and America are also noted in small rural communities in Australia. The establishment of threshold temperatures in all major rural regions of Victoria indicate that hot weather results in an increase in mortality in persons aged 65 years and older. This adds considerable strength to the argument that human populations are vulnerable to heat events regardless of location. Heat alerts can be issued through local health and welfare agencies, to increase awareness of ‘hot’ weather as a health hazard for elderly people by providing education campaigns involving local authorities based on these simple thresholds. [ABSTRACT FROM AUTHOR]

Abstract: This study analyzed the geographical patterns of heat-related mortality among the population aged 65 and over within the metropolitan area of Sydney, Australia between 1993 and 2004, and evaluated the role of some physical and socio-demographic risk factors associated with it. The effect of temperature on all-cause mortality during unusually hot days was investigated using spatial analytic techniques, such as cluster analysis and spatial regression analysis. Generalized Linear Models (GLMs) were used to investigate the role of daily average temperature, ozone (O3) and particulate matter of diameter less than 10μm (PM10) at the regions that showed a significant increase in mortality on unusually hot days. Spatial variation in mortality on unusually hot days was observed among the population 65 and over. Elderly people living within 5–20km south-west and west of the Sydney Central Business District (CBD) were found to be more vulnerable. However, analysis using GLMs showed temperature to be a significant modifier of daily mortality in the region to the south-west of the CBD only. O3 and PM10 were found to be non-significant factors in the regions where air pollutants were studied. Socio-economic status and the proportion of vegetation or developed land in each Statistical Local Area (SLA) were also not a significant factor explaining the increased mortality. A combination of social and environmental factors may be at play. Our results suggest an effect of temperature on mortality of the elderly population in Sydney Statistical Division at the SLA level. More spatially-based research would be beneficial once climate datasets with improved spatial coverage become available. [Copyright &y& Elsevier]

Green infrastructure has the potential to cool urban environments and reduce the health burden due to heatwaves. This study develops a new method to quantify the benefits of urban heat mitigation technologies on human heat balance and population mortality. The Heat Health Impact (HHI) method is based on the state-of-the-art, multi-parameter model, Universal Thermal Climate Index (UTCI). A proof-of-concept exercise applied the HHI method to Sydney, Australia (population = 5.7 million). All available weather stations (10) were selected for full spatial coverage of the Sydney region (12,367 km2), and average hourly UTCI was calculated from meteorological observations spanning the entire year 2017. In the baseline analysis, average daily UTCI values were calculated for each of the 10 observation sites, and then spatially interpolated across the entire Sydney region for Feb 9, 2017, a representative heatwave day for Sydney. Three different greening intervention scenarios were investigated, and daily average change in UTCI (ΔUTCI) was calculated under each by comparison with the baseline scenario; this ΔUTCI was named Urban Cooling Effect (UCE). We implemented a health impact assessment methodology to estimate the change in attributable mortality due to each greening scenario for the Sydney GMR population for the representative heatwave day. Urban greening infrastructure scenarios reduced daily average UTCI between −0.2 and −1.7 °C on the heatwave day, with the health impact assessment indicating heat attributable deaths reducing up to 11.7 per day across the Sydney GMR compared to the baseline scenario. Our results highlight the health benefits of greening infrastructure to cool urban environments. • A new method developed to quantify the benefits of urban greening on mortality. • Urban greening infrastructure reduced daily average UTCI between −0.2 and −1.7 °C. • Adaptation strategies reduced deaths up to 11.7 per day in Sydney during heatwave. [ABSTRACT FROM AUTHOR]

• Risk factors of heat death are varying at global, intermediate and local scales. • The multiscale GWR model yields a better fit of heat-related morality risk. • Hierarchical interventions are highlighted for effective heat health risk reduction. • Site-specific action plans are proposed for targeted climate adaptation strategies. Extreme heat is a leading cause of weather-related human mortality throughout much of the world, posing a significantly heavy burden on the development of healthy and sustainable cities. To effectively reduce heat health risk, a better understanding of where and what risk factors should be targeted for intervention is necessary. However, little research has examined how different risk factors for heat-related mortality operate at varying spatial scales. Here, we present a novel application of the multiscale geographically weighted regression (GWR) approach to explore the scale of effect of each underlying risk factor using Hong Kong as a case study. We find that a hybrid of global and local processes via multiscale GWR yields a better fit of heat-related mortality risk than models using GWR and ordinary least squares (OLS) approaches. Predictor variables are categorized by the scale of effect into global variables (i.e., age and education attainment, socioeconomic status), intermediate variables (i.e., work place, birth place and language), and local variables (i.e., thermal environment, low income). These findings enrich our understanding of the spatial scale-dependent risk factors for heat-related mortality and shed light on the importance of hierarchical policy-making and site-specific planning processes in effective heat hazard mitigation and climate adaptation strategies. [ABSTRACT FROM AUTHOR]

Urban tree cover contributes to human well-being through a variety of ecosystem services. In this study, we focus on the role that trees can play in reducing temperature during warm seasons and associated impacts on human health and well-being. We introduce a method for quantifying and valuing changes in premature mortality from extreme heat due to the changes in urban tree cover and apply this method to Baltimore City, Maryland. The model i-Tree Cool Air uses a water and energy balance to estimate hourly changes in air temperature due to alternative scenarios of tree cover applied across 653 Census Block Groups. The changes in temperature are applied to existing temperature–mortality models to estimate changes in health outcomes and associated values. Existing tree cover in Baltimore is estimated to reduce annual mortality by 543 deaths as compared to a 0% tree cover scenario. Increasing the area of current tree cover by 10% of each Census Block Group reduced baseline annual mortality by 83 to 247 deaths (valued at $0.68 –2.0 billion applying Value of Statistical Life estimates). Over half of the reduced mortality is from the over 65 year age group, who are among the most vulnerable to extreme heat. Reductions in air temperature due to increased tree cover were greatest in downtown Baltimore where tree cover is relatively low and impervious cover is relatively high. However, the greatest reductions in mortality occurred in the outskirts of Baltimore where a greater number of people who are over 65 years in age reside. Quantifying and valuing the health benefits of changes in air temperatures due to increased tree cover can inform climate adaptation and mitigation plans by decision makers. Developing adaptation strategies to effectively address these issues will become increasingly important in the future under changing climates and an aging population. [ABSTRACT FROM AUTHOR]

The excessively warm weather, especially in cities, can lead to several adverse impacts, including heat-related mortality, becoming an increasingly important public health issue. Previous studies on heat-related mortality have assessed risk factors at the municipal scale, missing the intra-urban variability in heat risk and vulnerability. The knowledge of the spatial intra-variability can help to design spatially targeted measures to better protect citizens' health. Through hot spot analysis, we identified the neighbourhood-scale spatial pattern of heat-related cardiorespiratory mortality in the elderly, during the yearly warmest five months of a three years period. Potential associations between spatial variability in heat-related mortality and several independent factors in each neighbourhood were investigated and their predictions. Two approaches were adopted: one is eminently statistical, using Generalized Linear Models (GLM) and another using Geographically Weighted Regression (GWR). This new recent regression technique is increasing in international attention on spatial modelling. The spatial model explains about 60% of the spatial variations in elderly's heat-related cardiorespiratory mortality. The two-analyses produced an overlapping set of predictor variables, with emphasis on the elderly, vegetation cover and employment. The results also show that the areas where heat-related mortality is high, are also the areas where the number of deaths is higher than expected. These neighbourhoods should be considered as the most vulnerable to heat-related mortality. We concluded that studying human health outcomes at neighbourhood-scale is relevant for public health heat-related plans. Essential suggestions are provided to decision-making support and city planners designing strategies to reduce heat-related mortality. Unlabelled Image • Multiple factors are associated with health effects of extreme heat. • We map the heat-related cardiorespiratory mortality in elderly at intra-urban scale. • Spatial variation in heat-related mortality is explained by age, greening and employ. • A reproducible approach with a recent technique that improves vulnerability assessment • This study is useful to provide more targeted information to city planners. [ABSTRACT FROM AUTHOR]

Seniors constitute the population group generally most at risk of mortality due to heat stress. As life expectancy increases and health conditions of elderly people improve over time, vulnerability of the population to heat changes as well. We employed the years-of-life-lost (YLL) approach, considering life expectancy at the time of each death, to investigate how population ageing affects temporal changes in heat-related mortality in the Czech Republic. Using an updated gridded meteorological database, we identified heat waves during 1994–2017, and analysed temporal changes in their impacts on YLL and mortality. The mean impact of a heat-wave day on relative excess mortality and YLL had declined by approximately 2–3% per decade. That decline abated in the current decade, however, and the decreasing trend in mean excess mortality as well as YLL vanished when the short-term mortality displacement effect was considered. Moreover, the cumulative number of excess deaths and YLL during heat waves rose due to increasing frequency and intensity of heat waves during the examined period. The results show that in studies of temporal changes it is important to differentiate between mean effects of heat waves on mortality and the overall death burden associated with heat waves. Analysis of the average ratio of excess YLL/death per heat-wave day indicated that the major heat-vulnerable population group shifted towards older age (70+ years among males and 75+ years among females). Our findings highlight the importance of focusing heat-protection measures especially upon the elderly population, which is most heat-vulnerable and whose numbers are rising. Unlabelled Image • Trends in heat-related mortality were investigated in the Czech Republic. • Years-of-life-lost approach was used to study effects of population ageing. • The frequency and intensity of heat waves increased during 1994–2017. • Mean effects of heat waves on mortality decreased while the overall death burden associated with heat waves increased. • The most heat-vulnerable population group shifted towards older age. [ABSTRACT FROM AUTHOR]

Abstract: We conducted a time-series analysis of 1997–1999 data records of air temperature and all-cause mortality in Greater Beirut, using bi-linear Poisson auto-regressive models, and published our findings in the Science of the Total Environment [El-Zein, A., Tewtel-Salem, M., Nehme, G., 2004. A time-series analysis of mortality and air temperature in Greater Beirut. Sci. Total Environ. 330, 71–80]. We compared our results to those of Curriero et al. [Curriero, F.C., Heiner, K.S., Samet, J.M., Zeger, S.L., Strug, L., Patz, J.A., 2002. Temperature and mortality in 11 cities of the Eastern United States. Am. J. Epidemiol. 155(1) 80–87.], who subsequently reported that their original results were inaccurate and published new results [Curriero, F.C., Heiner, K.S., Samet, J.M., Zeger, S.L., Strug, L., Patz, J.A., 2002. Temperature and mortality in 11 cities of the Eastern United States. Am. J. Epidemiol. 155(1) 80–87; Curriero, F.C., Samet, J.M., Zeger, S.L., 2003. Letter to the Editor re. On the Use of Generalized Additive Models in Time-Series Studies of Air Pollution and Health” and “Temperature and Mortality in 11 Cities of the Eastern United States”. Am. J. Epidemiol. 158(1) 93–94.]. In this letter, we report two changes in the interpretation of our findings as a result of the change in the results of Curriero et al. [Curriero, F.C., Heiner, K.S., Samet, J.M., Zeger, S.L., Strug, L., Patz, J.A., 2002. Temperature and mortality in 11 cities of the Eastern United States. Am. J. Epidemiol. 155(1) 80–87]. Their newly-reported results reinforce our conclusion that heat-related mortality can be a significant public health issue even in temperate to warm climates. However, our findings raise a question concerning the ability of socioeconomic indicators to explain differences in vulnerability to heat between high-income and low-income countries. [Copyright &y& Elsevier]