My intuition tells me that we tend to forget the ingenuity of humans a bit too quickly in this story of extreme humidity and heat.
Yes, humidity and heat are bothersome, but they are not a fatality everywhere, and they do not make a place uncomfortable without further ado.
In southern Italy, for example, people take siestas, have cool stone buildings, and develop habits that make summer very livable even with high humidity.
What would confirm my intuition is to see if the guide mentions local adaptation strategies beyond raw climate figures.