Key Points

Heat-related illnesses

• A new heat wave hit France at the end of week 26/2025.

• In Brittany, the heatwave began on Saturday, June 28, when Météo France issued a yellow heatwave alert for Ille-et-Vilaine. On Sunday, June 29, Monday, June 30, and Tuesday, July 1, Ille-et-Vilaine was placed under an orange heat wave alert and Morbihan under a yellow alert. On Wednesday, July 2, all Breton departments were downgraded to a green alert.

• In S26, heat-related illness indicators rose in parallel with the increase in temperatures observed during the episode.

• On Monday, June 30 (Week 27), there was a peak in emergency room visits, primarily affecting Ille-et-Vilaine (orange alert) and Finistère (green heatwave alert).

• Prevention tools for the general public and healthcare professionals are available for order or download on the Santé publique France website.

Allergies

• Another increase in emergency room visits in Week 26.

• The Capt’air Bretagne association maintains a high risk for grass pollen.