How to keep cities cool during heatwaves

Cities tend to get hotter than the countryside when a heatwave hits. What can be done about these urban heat traps? How can hot summers be made more tolerable for city-dwellers? SWI swissinfo.ch asked an expert at the federal technology institute ETH Zurich. Over 40°C in Barcelona, 42°C in Bucharest and peaks of 43°C in Foggia, in the south of Italy: the heatwave that descended on parts of Europe between the end of July and early August drove temperatures beyond averages experienced in the past. The heatwave also affected parts of Switzerland. The city of Lugano, in canton Ticino, experienced the longest period of heat in the past 160 years, according to MeteoSwiss. Heat gets particularly intense in cities. Asphalt and concrete just soak up the sun. They get overheated, and then retain the daytime heat after sundown. Furthermore, heat produced by vehicles and industrial actvity, together with the lack of green spaces and lack of ventilation, all contribute to the formation of urban ...