Each summer seems to beat a new record, but behind extreme temperatures hides a much more alarming reality. Heat episodes are no longer temporary anomalies, they are part of a trend that has permanently redrawn the European climate. While cities suffocate, another phenomenon is gaining momentum, often in silence. Mortality linked to heat waves is no longer an exception, it becomes one of the most disturbing indicators of climate change.
It is not a simple punctual disruption. The study published by the Imperial Grantham Institute underlines that the average temperatures of summer 2025 were 0.9 ° C higher than the 1990-2020 average on the entire continent. In 854 European cities studied, summer temperatures were on average 1.9 to 2.3 ° C higher than in a world without anthropogenic warming. This climate signal is not trivial. It becomes a direct vulnerability factor for millions of city dwellers.
In Eastern European countries, persistent heat coincided with a multiplication of fires and a deterioration in air quality. In Scandinavia, Finnish Lapland broke a heat record with 26 consecutive days above 25 ° C, a threshold formerly rare in the region. This climatic tilting no longer affects only southern areas, it becomes widespread throughout the continent.
Deadly mortality reveals a silent health crisis
The freezing figures put forward by the researchers reveal the extent of the drama. The study estimated that the heat had caused 24,404 deaths in the summer of 2025 in the 854 cities analyzed. Among them, 16,469 deaths would be directly due to global warming. This share represents 68% of summer mortality, a record that exceeds 54% already observed in the summer of 2023, according to Hundessa's analysis published in Cell Press.
In France, more than 1,400 dead have been identified among the cities studied. Rome, Paris, Madrid and Athens are among the most affected capitals. In Rome, more than 800 deaths are considered to be attributable to the heat linked to climate change. The elderly paid the heaviest tribute. 85% of the victims were over 65, and almost 10,000 were over 85 years old. This demographic distribution shows how the aging of the European population aggravates vulnerability to thermal extremes.
The researchers have not analyzed the death certificates, which rarely mention the heat, to obtain the figures for this study. They used a proven reference model based on the relationship between temperatures and mortality. This method highlights a largely invisible phenomenon in official health statistics. France 24 also confirms this by stressing that the authorities systematically underestimate heat-related deaths.
One case among others, relayed by The Guardian, illustrates this reality. That of Brahim Ait El Hajjam, a 47 -year -old worker who died by placing concrete on a site near Bologna while the temperature was around 38 ° C. He died two days before a regional decree prohibited external work in the middle of the day. An individual case embodying disturbing collective trends.
Adaptation is no longer enough in the face of climate run
Faced with the magnitude of the phenomenon, the adaptation devices quickly show their limits. Admittedly, the major European cities are better prepared in 2003, the year marked by 70,000 deaths, but emergency services and local policies remain insufficient. The study of the Imperial Grantham Institute also recalls that urban infrastructure, especially in densely populated areas, strengthen the heat effect. Concrete storks thermal energy and slows down natural refreshment, which accentuates the vulnerability of the inhabitants.
However, 70% of the European population now lives in the city, and this figure will reach 80% by 2050. The accumulation of threats linked to urbanization, demographic aging and climate makes adaptation more and more fragile. Indeed, current policies, if they remain unchanged, would lead to a warming of 2.7 ° C by 2100. Such a scenario would have an immense human cost, much higher than the already dramatic assessments recorded during the summer of 2025.
What the researchers show is that a two -speed action will no longer be enough. Protecting vulnerable people is crucial, but without rapid abandonment of fossil fuels, extreme temperatures will continue to progress. And with them, the number of victims.
