In 2016, health monitoring conducted as part of the Heat Wave and Health Alert System (SACS) under the National Heat Wave Plan (PNC) revealed the following in the Pays de la Loire region:- a heatwave in mid-July (July 17–20) that primarily affected western France and for which Météo-France placed the departments of Maine-et-Loire, Mayenne, Sarthe, and Vendée under an orange heat wave alert and Loire-Atlantique under a yellow alert. - This was associated with a slight increase in emergency room visits and SOS Médecins consultations for "heat-related" conditions (dehydration, hyperthermia/heatstroke, hyponatremia).- and a moderate excess in all-cause mortality of approximately 17% (+79 deaths) during the week of the orange alert. One heat-related death among a young construction worker was reported in Loire-Atlantique.

A retrospective analysis of this health surveillance confirms that health effects, particularly hyperthermia and heatstroke, are likely to occur during periods of sporadically high temperatures, even outside of actual heatwave periods. Although older adults remain the most vulnerable, hyperthermia also affects children and young adults. It is therefore important to reiterate preventive measures regarding proper hydration and limiting physical exertion, particularly for the most vulnerable (children and the elderly) and those exposed to heat (outdoor workers).