Maybe I'll start reading about Brazil. I've been to the most devastated areas of Brazil and there isn't overcrowding in Manuas. Their homes are built for the climate and it's still very warm during rainy season so they don't seal their homes. They're ventilated all year because of the humidity.

Hmm. It seems as though you've come to a conclusion and find evidence to fit this conclusion, but the best part of science is being open to all possible theories and testing the probability of each one.