Climate change is contributing to rapid and profound changes in the environment. At the same time, other factors—such as population growth and aging, as well as urbanization—are increasing vulnerability to various environmental and health risks. This creates a complex chain of interactions that affects people’s health and well-being. The development of preventive measures is necessary to reduce the health impacts of climate changes already observed (adaptation measures) and to limit the extent of global warming and thus its future impacts (mitigation measures). The mitigation goal requires major changes in several sectors of society, such as housing, agriculture, and transportation. Taking into account the potential health impacts of these changes is important to avoid choices that endanger human health and to maximize the associated health co-benefits. In this article, we offer a reflection on observed and future climate-related changes in France, and the challenges facing epidemiology and public health in the coming years. While many questions remain unanswered, there is now a consensus on the importance of the links between climate change and health, which can be summarized in three points: 1) climate change is already having impacts on health, 2) adaptation and mitigation are essential to reduce these impacts, 3) adaptation and mitigation can already rely on measures that will benefit both health and the climate. The significance and diversity of public health challenges, along with the many questions posed to research regarding surveillance or intervention, require an integrated and interdisciplinary approach.