Adapting will be expensive. With every degree of warming that gets locked into the climate system, the more it will cost to maintain something resembling normal life, and the more people there will be who are unable to afford it. The particular problem posed by heat isn’t that it’s impossible to adapt to, it’s that it’s difficult to adapt to equitably and in a way that doesn’t make the problem worse. Like mitigating climate change overall, any cooling solution will require collective action, in the form of international agreements like the Kigali Amendment, efficiency regulations, subsidies, technological advances, new building designs, and civic programs.
Needull in a haystack 
This was long but very interesting! Thanks
What a fascinating article. Of course, if climate change continues, as it most likely will, due to the short-termism of industry and business, there will be am exodus from the now uninhabitable countries to the cooler ones, thus creating all the problems we see now with people escaping from wars and political situations.
Of course, the arctic and Antartica may become habitable, thus relieving some of the pressure, but food may be a problem.