Urban heat islands are a new type of microclimatic phenomenon that causes a significant increase in the temperature of cities compared to surrounding areas. The phenomenon has been enforced by the current trend towards climate change. Although experts consider urban heat islands an urgent European Union public health concern, there are too few policies that address it. The EU carried out a project to learn more about this phenomenon through pilot initiatives. The pilots included feasibility studies and strategies for appropriately altering planning rules and governance to tackle the problem of urban heat islands. The pilots were carried out in eight metropolitan areas: Bologna/Modena, Budapest, Ljubljana, Lodz, Prague, Stuttgart, Venice/Padova, and Vienna. The feasibility studies carried out in these pilot areas focused on the specific morphology of EU urban areas, which are often characterised by the presence of historical old towns.