Amid a global climate crisis, more frequent and intense heat waves alter people's quality of life and increase morbidity and mortality. Cities are particularly vulnerable to heat because they concentrate people, including many in situations of individual, social and/or environmental fragility, and because the urban fabric, structure, cover and metabolism alter the thermal environment, which generally exacerbates heat stress. Creating cities that sustainably and effectively address the challenge of overheating is thus of utmost importance.