Key Points

A heat wave triggering the yellow and orange alert levels specified in the National Heat Wave Plan (PNC) occurred in mainland France between June 17 and 25, 2017.

This heat wave had distinctive features in terms of its environmental characteristics and its impact on health:

• Environmentally, this episode occurred early in the season and was geographically widespread, affecting, at its peak, nearly 87% of the metropolitan population—more than 56 million people.

• In terms of public health:

  • Regarding mortality, this episode shows: i) a 6% increase across all age groups (representing an estimated excess of 580 deaths), ii) more specifically, a 13% increase in the 15–64 age group (representing an estimated excess of 215 deaths), iii) a non-significant excess among those aged 65 and older. Additionally, 7 deaths were reported among workers. The hypotheses to explain these observed patterns in mortality are: for the 15–64 age group and the working population, the early onset of the event, which occurred outside the summer vacation period, and for the 65+ age group, a seasonal effect linked to the high mortality observed during the winter of 2016/2017.

  • Regarding healthcare utilization, we observe: i) a significant number (n=3,062) of emergency department visits for heat-related illnesses (HRI), ii) with a hospitalization rate of 52% (all ages) and 78% among those aged 75 and older, iii) a significant number of SOS Médecins consultations (n=1,460) for HRI.

The findings highlighted above regarding the health impacts observed during this early heatwave underscore the importance of strengthening prevention measures in the workplace, as well as among older adults.