https://news.climate.columbia.edu/2020/05/08/fatal-heat-humi...
The medium-term problem for these hot countries is that extreme heat negatively impacts education and economic productivity. Whenever there's a heatwave (which will become more frequent) they have to keep their kids home. Worker producitivity is negatively impacted. It's terrible for their economic development. The US and Australia and Canada continuing to pump more fossil fuels instead of simply building renewables does nothing help the average person in Sri Lanka living under 30+ degree heat. It is actively physically harming them in a very real way. It's an indirect, diffuse form of physical assault.
The long-term problem for these hot countries is that wet bulb temperatures will make it literally uninhabitable unless you have electricity and aircon, which many don't. This is not a matter of if, it's a matter of when. If we keep emitting, temperatures will keep rising, until the point that this becomes true. It is causality.
I want conservatives to think about this latter point because the consequences are mass immigration to colder countries, primarily the US and in Europe. Then the side-effect of that will probably be a rise in authoritarianism in these colder countries as a reaction to the mass immigration. None of this benefits anyone.