Headlines - The Heat Wave and Health Alert System

Designed and implemented since 2004 by the InVS in collaboration with Météo-France, the Heat Wave and Health Alert System (SACS) is a prevention and warning system for weather-related health risks.The system is operational every year from June 1 through August 31. Its objective is to identify in advance a heat wave likely to have a major health impact, in order to enable the rapid implementation of measures to prevent and manage the event.SACS is therefore based on the monitoring of meteorological indicators (temperatures, biometeorological indices (IBM), heat intensity, humidity, probability of exceeding IBM thresholds), which trigger the alert. These indicators were defined and selected for their relevance and proven link to mortality. It is the critical nature of these indicators, combined with the analysis of local contextual data (air pollution, large gatherings, etc.), that enables the InVS to issue a heat wave alert, formalized in a national alert bulletin. This bulletin is transmitted to health authorities and then disseminated across regions, supplemented with appropriate management measures. Starting the day after the alert, the joint analysis of meteorological and health indicators (mortality, emergency room visits for all causes across all age groups and among those aged 75 and older, emergency room visits for hyperthermia, dehydration, and hyponatremia; and use of the SOS-Médecins 87 association for all causes and all ages), along with any contextual data, enables the InVS to recommend whether to maintain or lift the alert. This surveillance is carried out regionally through a daily analysis of meteorological and health signals, with the production of a weekly summer surveillance bulletin outside of alert periods. The bulletin is published daily for the duration of the alert. Until August 31, the weekly Epidemiological Report will include, in addition to the indicators currently presented in the surveillance bulletin, weather and health indicators related to heat.

Trends:

• Overall emergency activity volume: Stable in emergency departments and decreasing for SOS-Médecins 17

• Gastroenteritis: Stable

• Asthma: Stable

• Allergies: Stable

• Mortality: Declining (unconsolidated data)

• Heat wave monitoring: No heat waves expected and normal fluctuations in health indicators.