Key Points

• In the Île-de-France region, the summer of 2023 was marked by unstable weather, with no heat waves in June, July, or August. The eight departments of the Île-de-France region were not classified as “orange alert” until late in the season, from September 8 through September 11, 2023, but the indicators remained relatively stable:

  • Stable use of healthcare services for all causes between September 8 and 10, but an increase on September 11; an increase in SOS Médecins calls and the iCanicule indicator, without an increase in hospitalizations.

  • Between September 8, 2023, and September 11, 2023, the proportion of emergency department visits among all age groups and those aged 75 and older increased, while remaining at low levels (less than 0.4% of total activity).

  • SOS Médecins calls related to iCanicule diagnoses increased as soon as the alert level was raised to yellow on September 5, 2023. Activity during the heatwave increased but remained at low levels.

  • An overall excess of 7 deaths (+0.7%) was estimated for this heatwave. The number of deaths attributable to heat was estimated at 560 [359–733] over the entire surveillance period, of which approximately 15% (n = 86) occurred during heatwave periods. Most (71%) involved people aged 75 and older. These heat-related deaths accounted for 8.1% of the mortality observed during heatwave periods and 2.8% of the mortality observed from June 1 to September 15.

• Link to the infographic