Extreme heat is not only making cities less livable; it is also reshaping who can afford to live where. The highest levels of vulnerability to climate gentrification are no longer found in the urban core, but in the metropolitan periphery. To help anticipate this process, researchers at the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) have developed the first metropolitan climate and housing vulnerability index for Barcelona, with data that can be explored street by street across 36 municipalities.