Who faces the highest risk of deadly heat?

Over the last couple of weeks there have been extraordinary heatwaves in North America. Heat records were broken across the Pacific Northwest, with temperatures over 40 degrees C in usually temperate cities such as Portland or Seattle. The full toll is yet to be counted, but authorities in British Columbia are reporting 500 or so heat-related deaths so far. Beyond the human casualties, the total harm of the heat wave will include damage to infrastructure, wildlife, agriculture, and the damage of...