Key Points

• According to Météo France, all departments in the Pays de la Loire region—Maine-et-Loire (49), Mayenne (53), Sarthe (72), Loire-Atlantique (44), and Vendée (85)—are under an orange heat wave alert. Tuesday will be the hottest day of the heat wave, with high temperatures ranging from 35°C to 40°C in the three departments in the eastern part of the region and remaining between 28°C and 37°C in the two departments in the western part of the region. Overnight from Tuesday to Wednesday, minimum temperatures will remain between 17 and 21°C. Maximum temperatures on Wednesday will drop. They will still range between 27 and 34°C in the eastern part of the region.

• A regional analysis of emergency care utilization shows no increase between June 29, 2025, and June 30, 2025, in emergency care utilization among people of all ages and those aged 75 and older for the iCanicule composite health indicator (including hyperthermia, dehydration, and hyponatremia) since the start of the episode that began on June 29, and thus two days into the heatwave. However, these data on emergency room visits should be interpreted with caution, as certain healthcare facilities in the Sarthe department—notably the Le Mans University Hospital—had not reported their data.

• For SOS calls in the metropolitan areas of Nantes and Saint-Nazaire in the Loire-Atlantique department (44), the proportion of SOS Médecins calls related to iCanicule among all coded calls (all ages) increased between June 29, 2025, and June 30, 2025. 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.