Key Points - A Look Back at the Heat Wave from August 5 to 14, 2020

France experienced a heat wave from August 5 to 14. This event was the subject of daily analyses, the last of which was dated August 18.

The heat wave began on August 5, when 32 departments were placed under a yellow alert. Starting on August 6, 54 departments were placed under an orange alert across 10 regions (Auvergne-Rhône-Alpes, Grand-Est, Occitanie, Normandy, Nouvelle-Aquitaine, Centre-Val de Loire, Bourgogne-Franche-Comté, Pays de la Loire, Île-de-France, and Hauts-de-France). The following day, 15 departments in 3 regions (Ile-de-France, Hauts-de-France, and Normandy) were placed under a red alert. The red alert was lifted on August 12 in the departments of the 3 affected regions. All orange heatwave alerts were lifted on August 13, and the yellow alerts on August 14.

This was a prolonged and widespread heat wave, characterized by very high nighttime temperatures. Nationally, according to Météo-France, this heat wave was as severe but less intense than the one observed in 2019. It was comparable to the 2003 heat wave in Hauts-de-France and was one of the most severe heat waves since 2003 in Île-de-France and Normandy.

In Bourgogne-Franche-Comté, all 8 departments were placed under an orange alert between August 6 and August 12. During this period, an increase was observed in the proportion of emergency room visits for the composite iCanicule indicator (hyperthermia, dehydration, hyponatremia, all ages combined). The same was true for the proportion of hospitalizations related to iCanicule (all ages) among coded hospitalizations. No increase in the proportion of SOS Médecins calls related to the iCanicule indicator was observed during the same period, across all age groups.

These health impacts serve as a reminder that heat poses a health risk. It is important to anticipate heat waves and implement the preventive measures recommended by the national heat wave management plan (2).