My mother lived in Phoenix in the 1920s and said she didn’t remember it being bad before coolers. They just weren’t used to them like we all are now. They had screened sleeping porches because it was too hot to sleep indoors at night. They did have electricity though- I think she said they had ceiling fans. But Indians and Hispanics lived in that desert before there was any way to cool it. There were fewer people but they were able to survive in the desert.
During the depression my mother’s family moved to Camp Verde because life was really tough in Phoenix with so many without work. Talk about basic survival, my grandmother was a widow with 5 children when the depression hit and my mother said they lived for months on corn meal mush and very little else. Once they moved to Camp Verde they had a place for a garden and could fish and hunt. My mother said she thought Camp Verde was a paradise compared to Phoenix. It is hard for us to imagine living a life based on sheer survival, but many before us have done it- and there are many on this planet doing it right now so it can be done when it comes right down to it. I admit the large population would make it harder but I would think anything so catastrophic that it could take us back to that point would likely kill many, many people. Mankind in general is tough and you just don’t know how little it takes to survive when you have no choice.
I don’t know how old you are, but I grew up around adults that went through the depression and their stories were heartbreaking. I had an uncle that said they would work hard in the fields all day long in the hot Texas panhandle and then come home at night and many times they had very little or nothing to eat before they could harvest so would just go hungry for days until his dad could manage to kill something or trade for some food or money. My mother knew people that had to give up their children because they could not feed them. The scary thing was everyone of them would tell some terrible memory of the depression and then tell you they knew people worse off than they were. Many died during the depression, but most survived somehow.
That’s something we never hear about - those who died during the Depression due to the Depression.