The heatwave of 2003 remains etched in our memories. We remember an angry emergency doctor, crowded hospital corridors, and a health minister in a polo shirt who seemed completely out of touch with reality. Between August 1 and 20, 2003, the heatwave claimed 15,000 lives. One in three victims lived in the Ile-de-France region, which was hardest hit by this deadly heatwave. This tragedy revealed many shortcomings. First, the lack of preparedness of the public authorities to deal with such a health crisis. Second, the way in which the elderly are treated. Climatologists estimate that from 2050 onwards, the summer of 2003 will be the norm. Hyper-urbanization, poor insulation in homes, and a lack of green spaces are all factors that exacerbate the effects of high temperatures.