Europe’s deadly early summer heatwave has been linked to more than 1,300 excess deaths since June 21, according to World Health Organization Director-General Tedros Adhanom Ghebreyesus.
Tedros said on X that extreme heat had closed schools, strained power grids and put millions of people under dangerous conditions.
He warned that heat stress is often called the silent killer because many deaths happen quietly inside homes, hospitals and care settings.
France’s public health agency reported around 1,000 additional deaths during three of the worst days of the heatwave.
The agency said more than 1,200 deaths were recorded on Wednesday, followed by more than 1,400 deaths on each of the next two days.
Before the heatwave, France had been recording about 900 to 1,000 deaths per day in April and May. Officials said the estimate may rise as more death data is collected.
The agency said 85 percent of the deaths involved people age 65 or older. The sharpest increase came in areas under red heat warnings.
Germany recorded its hottest day on record for the third day in a row, with 41.7C reported in Neissemunde-Coschen near the Polish border.
Poland also broke its all-time record with 40.5C in Slubice. Czechia reached 41.9C, marking its hottest day ever.
The heat moved east after breaking records in western Europe, where France, Spain, Switzerland and the United Kingdom had already faced extreme temperatures.
The heatwave has also led to deadly water risks as people try to cool down in rivers, lakes and other unsupervised areas.
French Interior Minister Laurent Nunez said 74 people drowned between June 18 and June 27, according to reports citing his interview with Le Parisien.
Many deaths happened in natural bodies of water, where cold water shock, strong currents and lack of lifeguards can turn a swim into an emergency.
The WHO says the European Region is warming at about twice the global average rate.
In a 2024 statement, WHO Europe said heat stress is the leading cause of climate-related death in the region.
Extreme heat can worsen heart disease, lung disease, diabetes and mental health conditions. It is especially dangerous for older people, people living alone and those without access to cooling.
A rapid study by World Weather Attribution found that this heatwave would have been virtually impossible without human-caused climate change.
The study, reported by AP, said similar heat is now 200 times more likely than it would have been 20 years ago.
Researchers also found that 45 percent of 850 cities studied across 30 European countries had broken, or were expected to break, records for heat stress.
The heatwave has exposed how many European homes, schools and workplaces were built for colder weather, not repeated days above 40C.
Tedros urged European countries to strengthen heat-health action plans, including better warnings, cooling spaces, public health checks and stronger emergency response.
With the heatwave still affecting parts of Europe, officials are urging people to stay hydrated, avoid the hottest hours, check on older neighbors and seek help quickly if heat illness symptoms appear.