Key Points

• According to Météo France, all departments (Paris, Seine-et-Marne, Yvelines, Essonne, Hauts-de-Seine, Seine-Saint-Denis, Val-de-Marne, Val-d'Oise) in the Île-de-France region were placed under a yellow alert on Monday, August 11, 2025. Since August 12, 2025, all 8 departments in the Île-de-France region have been placed under an orange heat wave alert. This alert ended on August 15, 2025, for the entire region.

• Regional analysis of emergency care utilization indicates an increase in visits and a stabilization in the proportion of hospitalizations following emergency room visits for the composite health indicator iCanicule (including hyperthermia, dehydration, and hyponatremia) since the start of the heatwave.

• Regional analysis of SOS Médecins consultations indicates an increase in the iCanicule composite health indicator (heatstroke, dehydration) throughout the episode.

• This trend falls within the expected fluctuations for the current weather conditions and is observable across the region as a whole.

• Heat poses a health risk to the entire population. The observed health impacts underscore the importance of implementing preventive measures to mitigate the effects of heat.