Study Estimates Record 50,000 Heat Deaths in European Cities This Summer

The study modelled historical relationships between heat and health across 854 cities and found the toll was the worst on record. It estimated that heat added by pollution cut short an extra 32,000 lives in urban areas from June to August. Morgues and funeral homes filled with bodies as hot days pushed vulnerable people into overdrive and warm nights prevented them from recovering. The death toll was nearly twice as high as in each of the two next most dangerous years, the researchers found.

"In some sense, the absolute numbers of the heat-related deaths estimated across the 854 urban areas are indeed staggering," said Malcolm Mistry, a climate and health scientist at the London School of Hygiene & Tropical Medicine and a co-author of the study. "But perhaps what is even more alarming is the proportion of these deaths that we attribute to anthropogenic climate change."

The share of deaths linked to climate breakdown rose from about 40% at the start of the century to 65% this summer, the study found. Death rates were highest in Malta, Italy and Hungary, while absolute tolls were greatest in Italy, France, Spain, Germany and the UK. Death certificates rarely record contributing factors such as dangerous temperatures that push a stroke victim or lung cancer patient past their limits, so families rarely know that heat and human activity hastened a relative's death.

"These shocking figures represent thousands of families who have lost a loved one this summer due to the climate crisis," said Katie White, the UK's climate transition minister. Scientists estimated 4,354 heat deaths in the UK this summer.

Naples was the hardest-hit city, with 815 deaths per million people in age-standardised estimates. Mario Guarino, an emergency doctor at Ospedale CTO in the north of the city, said emergency room visits rose 15% during the hottest weeks. He said the period's "defining characteristic" was the complexity of health problems worsened by heat, with loneliness and poverty making conditions worse. He described treating a terminal cancer patient who lived in a hot attic because his family could not find a company to install air conditioning during the summer, and an elderly man with dementia who was abandoned by his Ukrainian caregiver after she returned home to say goodbye to her son, who had been called to war. Emergency services found the man on the floor one night with a fractured pelvis, trying to call the tenant next door.

People over 85 made up almost half of the death toll, the study found, though younger people were not immune: 833 people between 20 and 44 were also thought to have died because of the heat. The scientists said the toll from the cities studied, which account for about 40% of Europe's population, could not easily be extrapolated to estimate deaths in towns and villages.

The EU's climate monitoring service announced this month that the heat that persistently baked western Europe this summer was the worst on record. More than half the continent was seared by "very strong" heat stress that felt hotter than 38C, while slightly less punishing temperatures in eastern Europe brought the continental average to its third-hottest level on record. Greenhouse gases have warmed Europe about twice as fast as the global average, exposing more people to intolerably hot summers and fewer to dangerously cold winters. Cold is a bigger killer than heat, but scientists expect rising temperatures to claim more lives than they save as heat deaths rise faster than cold deaths fall.

The study combined established relationships between heat and mortality with temperature data for 2026 to rapidly estimate the fallout from this summer's heat. Death tolls for individual countries differ from those calculated by national public health agencies using their own methods. David García-García, a researcher at the mortality monitoring system at the Carlos III health institute in Madrid, who was not involved in the study, said it was a "valuable contribution" that allowed comparisons across the continent. "However, it is important to bear in mind that these are estimates based on observed temperatures and epidemiological models, which do not incorporate actual data on deaths occurring in the summer of 2026," he said.

Doctors have urged governments to burn fewer fossil fuels and to strengthen health systems, green cities, roll out air conditioning and encourage people to drink water and seek shade.