🌡️ 63,000 heat-related deaths in Europe during summer 2024: an effective new prediction system

The precise quantification of heat-related deaths is a major challenge for public health. A study published in Nature Medicine provides a detailed analysis for the summers of 2022 to 2024. It is based on the analysis of daily mortality data, a more precise method than the weekly estimates used previously. This approach has enabled the development of a high-performance early warning system.

A devastating human toll

The summer of 2024 was the hottest ever recorded in Europe. Researchers estimate 62,775 heat-associated deaths during this period. This toll is lower than that of the summer of 2022 but 24% higher than that of 2023. This variability is explained by the intensity and location of the heatwaves.


Southern European countries bear the heaviest burden. Italy and Greece have the highest mortality rates. The vulnerability of these regions is exacerbated by their demographics and socio-economic conditions. Heat particularly affects populations over the age of 75.

Women are significantly more affected than men. Physiological differences and social factors could explain this gap. People suffering from pre-existing heart or respiratory conditions constitute other high-risk groups. Their bodies cope less well with the additional strain induced by the heat.

An innovation in risk forecasting

The Forecaster.health system relies on a method integrating multiple data sources. It combines detailed weather forecasts with local indicators of social and health vulnerability. This approach makes it possible to assess the potential impact of a heatwave on a specific population.

The method uses epidemiological models calibrated on historical daily mortality data. These models establish a precise relationship between observed temperatures and deaths that occurred in the past. They are then applied to temperature forecasts to anticipate future mortality.

Researchers tested the system's reliability on data from the summers of 2022 to 2024. The results show an ability to predict health emergencies with great accuracy up to seven days in advance. The performance is particularly robust in Southern Europe, a highly vulnerable region.

This methodological advance provides a window of action for public health authorities. It transforms a simple weather forecast into an operational crisis management tool. The goal is to enable targeted interventions to protect the most at-risk populations.

To go further: How does excessive heat affect the human body?

In the face of intense heat, the body activates two main mechanisms to maintain its internal temperature. The heart rate increases to supply blood to the skin and promote heat dissipation. Sweating also allows for cooling through evaporation.

These processes place a significant strain on the cardiovascular and respiratory systems. For a frail person, this additional load can become critical. The body, like an overheating computer, can experience a degradation of its vital functions.

The main risk is heatstroke, a failure of the thermoregulatory system. This leads to dehydration and thickening of the blood. These phenomena can cause heart attacks, strokes, or the worsening of chronic diseases.