The purpose of this article is to provide an overview, two years after the heat wave, of the main studies conducted in France in the wake of this tragic event, their findings, and the resulting recommendations for prevention policies, which have since been significantly expanded since August 2003. We will also review the current state of knowledge regarding the impact of heat waves in other European countries and the prospects for EU-level work on the subject. To assess the usefulness of these studies in informing decision-making, we will describe how their findings and recommendations have been incorporated into the development of prevention measures. (Excerpt from the introduction)