The impact of high temperatures associated with climate change on the total number of heat-related deaths was thus 68% this summer, concludes the study, led by experts from the British institutions Imperial College London and the London School of Hygiene and Tropical Medicine.

Data collection took place between June 1st and August 31st, and the study results represent approximately 30% of the European population.

This is the first large-scale estimate of the health impacts of a summer marked by particularly high temperatures in Europe.

Several heat waves were observed, and the summer was the hottest on record in several countries, including Portugal, Spain, and the United Kingdom.

Scientists studied the influence of climate change on daily temperatures in 854 cities and found that they were, on average, 2.2 degrees Celsius above normal due to fossil fuel burning and deforestation

Italy was the country whose cities were most affected by the heat's impact, causing 4,597 deaths, followed by Spain (2,841), Germany (1,477), France (1,444), and the United Kingdom (1,147).

Some of the most affected European capitals were Rome (835 deaths), Athens (630), and Paris (409), according to the data.

People over 65 account for 85% of heat-related deaths, and the study highlights "the growing threat posed by extreme summers to an increasingly elderly European population."

Researchers describe extreme heat as a "silent killer," as many deaths go unreported and official figures can take months to be released.

The scientific team calls for strengthening heat protection policies. The most effective measure to curb mortality is to accelerate the transition from fossil fuels to renewable energy, according to the study.

Friederike Otto, Professor of Climate Science at Imperial College London, highlighted the direct link between fossil fuel use and the deadly impact of heat waves.

"The chain from the burning of oil, gas, and coal to rising temperatures and mortality is undeniable," said Otto.

The scientist adds that if dependence on these fuels had not continued in recent decades, "most" of the approximately 16,500 deaths could have been avoided

The risk will increase in the coming years if the energy transition is not accelerated, according to experts.

"This century, we are on track to reach temperatures of up to three degrees Celsius, which will bring much hotter and deadlier summers to Europe," said Otto.