The warm summer of 2018 - increased mortality among older people?

Background: Heatwaves in Europe and the USA have been shown to cause excess mortality among older persons. The summer of 2018 was unusually hot in south-eastern Norway. The purpose of this study was to investigate whether more older persons died that summer compared with the average for the previous ten summers.
Material and Method: Temperature data from the Norwegian Meteorological Institute and mortality data for the summer of 2018 (June, July and August), divided into age groups and counties, were compared to the previous ten summers.
Results: For Norway as a whole, there was no increase in mortality among persons more than 75 years and 85 years of age in summer 2018. None of the counties in south-eastern Norway stood out as having elevated mortality for persons more than 75 years of age, apart from Vest-Agder county. Three counties, among them Aust-Agder, had somewhat lower mortality than expected.
Interpretation: We are unable to show any increase in mortality among older persons in summer 2018 compared with the average for the period 2008-17. Due to climate change and prognoses of more frequent heatwaves, mortality should nevertheless be monitored and public warning systems considered.