Key Points

In mainland France, June and July 2019 were marked by two widespread and intense heat waves. During these two heat waves, for the first time since the implementation of the National Heat Wave Plan (PNC), mainland departments were placed on red alert due to exceptionally high daytime temperatures.

In Bourgogne-Franche-Comté, these two heatwave episodes led to alert thresholds being exceeded in seven departments (with the exception of Nièvre) during the first episode in June and across the entire region during the second episode. On this occasion, one department (Yonne) was placed under a red alert for the first time (for two consecutive days). A significant impact on health was observed during these periods:

• During the periods when alert thresholds were exceeded and for the affected departments in the region, 83 [17–155] excess deaths were estimated, representing a relative excess mortality rate of +7%. The more intense heatwave in July alone accounted for nearly 49 deaths. People aged 75 and older accounted for the vast majority of excess deaths during both episodes.

• Heat-related conditions (defined by the iCanicule indicator, which includes hyperthermia, dehydration, and hyponatremia) accounted for up to 4% of emergency department visits and 8% of SOS Médecins calls during the first episode. During the second episode, this activity was lower, though it still accounted for more than 3% of emergency room visits and more than 4% of SOS Médecins calls. The hospitalization rate following an emergency room visit during these two episodes was 49% and 46%, respectively.

The health impacts of heat observed in this study were not limited to these periods alone, as half of the emergency department visits and more than two-thirds of SOS Médecins calls occurred outside of these two heat waves.