Between June and September last year, 62,775 people lost their lives to extreme heat, according to a study led by the Barcelona Institute for Global Health (ISGlobal). The figure represents a 23% increase compared with 2023, confirming that 2024 was Europe's hottest summer on record, based on data from the EU's Copernicus Climate Service.
The study examined 654 regions across 32 countries and found that more than 181,000 deaths from 2022 to 2024 were heat-related. Researchers warned that official numbers may even understate the true scale, as heat often worsens existing medical conditions, particularly among the elderly.
Italy recorded the highest number of fatalities — over 19,000 in four months — driven by sweltering 40°C temperatures in cities such as Rome and Palermo, combined with the country's ageing population. Among people over 75, the risk of dying from heat was more than three times higher than in younger groups, and women were disproportionately affected, with deaths 46% higher than men.
Spain (6,743 deaths), Germany (6,282), Greece (5,980) and Romania (4,943) were also among the worst-hit nations. But when adjusted for population size, Greece faced the deadliest impact, with 574 heat deaths per million people — far exceeding previous years.
Scientists warned the Mediterranean and southeastern Europe are becoming climate change hotspots, with heat mortality expected to rise sharply through this century.
"Europe is warming at twice the global average," said lead author Tomáš Janoš of ISGlobal, adding that the region faces escalating health risks without stronger adaptation measures.
Last summer also saw deadly wildfires, closures of tourist sites and a string of workplace tragedies, including the deaths of outdoor workers in Spain and Italy during heat alerts.
Experts argue that climate change has intensified the continent's heatwaves, with researchers at Imperial College London estimating that nearly 70% of heat deaths in 2025 can be attributed directly to human-driven global warming.
Health specialists are urging governments, especially in southern Europe, to prepare with better housing design, public health planning and access to cooling. Unlike the US, where nearly 90% of homes have air conditioning, only around 20% of European households are equipped to deal with extreme heat.
"Heatwaves are silent killers," warned Dr Garyfallos Konstantinoudis of Imperial College London. "Without urgent adaptation, Europe will face mounting human costs each summer."