Heat-related mortality in Europe during 2023 and the role of adaptation in protecting health

The year of 2023 was the warmest on record globally and the second warmest in Europe. Here we applied epidemiological models to temperature and mortality records in 823 contiguous regions from 35 countries to estimate sex- and age-specific heat-related mortality in Europe during 2023 and to quantify the mortality burden avoided by societal adaptation to rising temperatures since the year 2000. We estimated 47,690 (95% confidence interval 28,853 to 66,525) heat-related deaths in 2023, the second highest mortality burden during the study period 2015–2023, only surpassed by 2022. We also estimated that the heat-related mortality burden would have been +80.0% higher in absence of present-century adaptation, especially in the elderly (+100.7% in people aged 80+ years). Our results highlight the importance of historical and ongoing adaptations in saving lives during recent summers and the urgency for more effective strategies to further reduce the mortality burden of forthcoming hotter summers.