Seasonality reversal of temperature attributable mortality projections due to previously unobserved extreme heat in Europe

Climate change is impacting human health. The 2020 report of the Lancet Countdown on health and climate change1 estimates a 53·7% increase in heat-related mortality in people older than 65 years during the past 2 decades. Nowadays, most of the record-breaking temperature extremes are directly attributable to climate change,2 and these events are continuously redefining the range of observed climatological temperatures to which populations are exposed. These previously unobserved temperatures pose an additional threat to human health, as exemplified by the record-breaking heatwave in the summer of 2003, which caused a mortality excess of more than 70 000 premature deaths in Europe.