In August 2003, France sustained an unprecedented heat wave that resulted in 14,800 excess deaths. The consequences were maximal in the Paris area. The Assistance Publique-Hôpitaux de Paris reported more than 2600 excess emergency department visits, 1900 excess hospital admissions, and 475 excess deaths despite a rapid organization. Indeed, simple preventice measures before hospital admissions are only able to reduce mortality which mostly occurred at home and in nursing homes.