Europe's Heat Toll: 50,391 Dead as Fossil Fuels Warm

Heat waves across Europe in June, July and August 2026 killed an estimated 50,391 people in 854 cities, researchers said. They attributed 32,619 deaths to extra heat caused by burning coal, oil and gas. The estimate comes from a study published in an upcoming issue of Nature Health. It exceeds the toll from the analysis’s previous deadliest summer, 2022, by 71%; 29,480 people died that year.

The figures cover cities with about 40% of Europe’s population and leave out a deadly heat wave in May. Researchers say the toll is an underestimate. Konstantinoudis said heat deaths often go unreported and don’t appear on death certificates; his team used statistical modeling to estimate deaths that official records can miss.

The numbers behind the heat

About one-third of the deaths occurred during an especially intense heat wave from June 17 to July 1. Temperatures then ran 9.5 degrees Fahrenheit (5.3 degrees Celsius) above normal, said study co-author Garyfallos Konstantinoudis, a biostatistician at Imperial College London. Lead author Clair Barnes, a climate scientist at Imperial College London, said some European cities recorded temperatures 21.6 F (12 C) above normal.

Italy, France, Spain and Germany had the highest death tolls. In a separate analysis, the researchers found Rome had the highest heat death total among European capitals from 2000 to 2025.

“Much of Western and Northern Europe, our infrastructure is just not designed to cope with the sort of temperatures that we are seeing now because of the effects of human-caused warming,” Barnes said. Europe is 4.5 F (2.5 C) hotter than in pre-industrial times, she said, and is the fastest-warming continent, although the Arctic is warming faster.

“Just the underlying warming from human activity, from mostly the burning of fossil fuels, it's increasing all of our temperatures by what sounds like quite a small amount,” Barnes said. “For many people, it's certainly the case that that extra two-and-a-half degrees (Celsius) of warming is what's going to tip those temperatures from uncomfortable to dangerous and potentially deadly.”

More than half of those who died were 85 or older. Heat also killed more than 800 people aged 20 to 44, Konstantinoudis said. The researchers compared computer simulations of a world without climate change with deaths recorded during the summer, and attributed the difference to global warming. Barnes said the share of heat deaths attributed to global warming has risen from about 45% in the early 2000s to 65% now.

What the records leave out

The researchers used a mathematical equation from previously peer-reviewed studies. It accounts for each city’s age profile and temperatures, measured against the local temperature associated with the fewest deaths. They also compared their calculations with government estimates. For British heat waves in May and June, their method calculated 2,700 excess deaths; the United Kingdom health statistics agency estimated 2,800.

“Summers are getting hotter, and the analytical tools for attributing deaths to heat are getting more accurate,” said Dr. Howard Frumkin, former director of the National Center for Environmental Health in the U.S., who wasn't involved in the study. He said the two trends produce increasingly high and increasingly accurate counts of heat-related deaths. Outside experts agreed with the researchers' methods and described them as state-of-the-art.

Cooling, prevention and the cost

“We need to prepare for the heat we cannot now avoid, with urgent investments in heat early-warning systems, equitable access to low-carbon cooling, and neighborhood buddy systems that check on and support people most at risk — while rapidly reducing the fossil fuel use driving the crisis,” said Dr. Courtney Howard, a Canadian emergency room physician and president-elect of the Canadian Medical Association, who wasn't part of the research.

Dr. Jonathan Patz of the University of Wisconsin-Madison, also not involved in the study, said: “We can't just be mopping up the mess on the floor without thinking about turning the faucet off. So we need prevention at different levels. We need better cooling and protecting vulnerable populations from inevitable increased frequency and extreme heat waves. But we also need to go to the root of the problem and absolutely address the burning of fossil fuels.”

A separate Bloomberg report put the summer heat death toll in European cities at about 50,000, calling it the highest on record. It said the heat reduced European Union gross domestic product by roughly 0.17% from April through September, or close to €17 billion ($18.9 billion). Two separate studies supplied the figures. The death toll and economic hit sit in the same summer's ledger.