Key Points 

Extreme Heat, Heat Wave 

• Brittany experienced its first heatwave of S22 (May 26–28, an early occurrence), affecting the entire region. Record-breaking temperatures were observed.
• The seasonal monitoring system has been active since June 1 and will remain so until September 15.
• A new heatwave struck France from June 18 to June 28. This widespread, prolonged, and intense heatwave was nearly as severe as—or equivalent to—the one in 2003, breaking new temperature records.
• In Brittany, the heatwave occurred from June 21 to 27. All departments were placed under a red alert from June 22 to 25 (except for Ille-et-Vilaine on June 26).
• A very significant increase in emergency room visits and SOS Médecins consultations was observed during this heat wave alert period. The indicators reached unprecedented levels, never before observed since the monitoring system was established.

Asthma

• The number of SOS Médecins consultations remained stable, with a slight decrease in emergency room visits across all age groups, particularly among those under 15 years of age.

Allergies

• The number of emergency room visits remained stable. The number of SOS Médecins consultations increased slightly above the rates for 2025 and 2024 during the same period.

Gastroenteritis

• High activity. An increase in emergency department visits, with a corresponding decrease in SOS Médecins consultations.

ENT Conditions

• Moderate to low activity related to ENT conditions. In Week 26, among children under 5 years of age, ENT conditions accounted for 12% of emergency department visits (11% in Week 25) and 38% of SOS Médecins consultations (49% in Week 25).
• The virology laboratories at the Rennes University Hospital and the Brest University Hospital detected rhinoviruses/enteroviruses in 41% (12/29) and 16% (15/92) of the samples tested, respectively.