Key Points 

• From May 25, 2026, to May 29, 2026, Météo-France issued a heat wave advisory for three departments in Normandy (La Manche, Orne, and Calvados). On May 26, 2026, La Manche was upgraded to an orange heat wave alert, which remained in effect until May 28, 2026. 
• A regional analysis of emergency care utilization indicates an increase in the composite health indicator iCanicule (covering hyperthermia, dehydration, and hyponatremia) from the start of the heatwave compared to baseline levels.
• The trend in the indicators monitored in emergency departments is consistent across departments, with an increase in indicators observed in all departments except Calvados
• The trend in indicators monitored for the SOS Médecins associations is consistent across the associations, with an overall increase in indicators observed and the sharpest rise noted in the Caen association.
• 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.