Most people farmed back then, so they got up and got their work down early and when it got hot they sat in the shade. Many slept outside on the porch to catch a little air movement, and the houses had large windows to allow in the breeze if there was any. Winter and the cold would have been much worse than summer time for these people. Houses that were always cold and going out to the outhouse in January could not have been worse.
I grew up in the 1960s and 1970s in farmhouses that had no air conditioning. It just got hot, you dealt with it. Lots of days spent in front of fans, doing what you could to try to cool down. Every night we had fans in our bedroom windows, at least bringing in the night air into the house. When my brothers and I were out with Dad in his pickup truck, we’d beg him to turn on the AC, but he’d never do it. He’d tell us, “You’ll just feel hotter when you have to get out.”
I’m not saying it made me tougher, I didn’t like it (and baling hay in temperatures like this was torture), but what are you gonna do? This week I hardly ever went outside, it was so gross.