To me the heat can be dealt with far more than the cold. That being said humidity is almost a killer. 105 with low humidity, often here it is as low as 5 percent, I can still do some outside work and exercise. Shorter and less strenuous I agree. But twice in my life high humidity has almost struck me down. So I am very careful to monitor my HR and fluid and electrolyte intake. Still this is a consideration. https://www.theweathernetwork.com/ne...man-body/51464

However when I lived in the northern part of our country the cold has almost paralyzed me. Exercising in Montana in the deep winter even after a few weeks with my sister was just not going to happen outside. I had the clothing, I looked like an Eskimo, and after just a few minutes glove-less hands were out of the question. At least for me, and I have lived when it gets cold for many years, cold is the worst. Having had my power knocked out I simply don't accept people can adapt to not using a heater or fireplace. Having also lived in the desert I don't see why someone would live without air conditioning if it is available.