Isabelle Daëron studies temperature rises in urban areas. The large, densely built cities usually have little vegetation, which means they retain a lot of heat. This creates the heat islands effect, where it becomes up to 13 degrees warmer on the hottest days than outside the city. In Paris the average temperatures per day are already around 2 to 3 degrees higher compared to the rest in the region. In summer this can be as high as 10 ° C. For the heat problem in Paris, Daëron designed the Aéro-Seine, a cooling system for the city that uses undrinkable water from the river. The Aéro-Seine design can be processed in the streets of Paris, and activated in times of high temperatures by the supply of water. Once opened, the water rises in a small tank and then flows through a grid. The water spreads on the porous surface and evaporates, cooling the surrounding air. The system uses the non-potable water network built in the 19th century. This network also provides water for public parks and cleans the streets. In this way drinking water can be saved and stored.