A new study says that black people living in most US cities are subject to double the level of heat stress as their white counterparts. The researchers say the differences were not explained by poverty but by historic racism and segregation. As a result, people of colour more generally, live in areas with fewer green spaces and more buildings and roads. These exacerbate the impacts of rising temperatures and a changing climate. Cities are well known magnifiers of a warmer climate. The surface urban heat island effect is the technical term for the impact that the buildings, roads and infrastructure...