Heat stress from extreme heat and humidity is expected to annually affect areas now home to 1.2 billion people by 2100, assuming current greenhouse gas emissions.. That’s over four times the number of people affected today. Global warming makes hot, humid days more frequent and intense. Heat stress is caused by the body’s inability to cool down properly through sweating.
https://www.sciencedaily.com/releases/2020/03/200312142256.htm