I really don’t see how it’s possible to live in any country in the SEA region, Middle East or Africa because the heat alone will probably make people unproductive and air conditioning runs up the energy cost. It’s only northern countries that can avoid those productivity losses so I think anyone who lives below the equator will have to move north.
I mean I live in Canada and there are some parts of my country (in the North Pole) that are freezing all year round but they are just tiny settlements and are not developed enough to sustain millions of people yet.