[burntoutfire]

I imagine this happening only in the least well-run countries. In any country with a functioning military, they'll probably organize a mass operation of moving people into temporary refugee camps in cooler areas of the country or into caves, underground structures etc. For people who won't be moved, they'll provide food and water for them so that people don't need to leave their hiding places during the day. (Also, I suspect that, after first major killer heat wave hits an area, people will have their own contingency strategies - be it digging a cellar for themselves to stay in, move to relatives in cooler areas for the duration etc.). However, I'm not sure if for example India is organized enough to pull this off, given their absolutely massive population.

[nradov]

The countries that will be most affected generally don't have well-run militaries either. We're talking about places like Bangladesh and El Salvador.