Most of the places I’ve lived in the US nearly everyone has air conditioning these days… including nearly all businesses & public buildings.
When I was a kid, it was more 50/50. Some regions might have had more, but in Southern California, Louisiana, South Carolina, Virginia? Certain businesses (shopping malls, movie theatres, etc.) had air conditioning, and people headed there en masse when it got hot; but most schools/etc. did not, and only the richest & poorest had air conditioning in their homes (swamp coolers in poor homes, where water damage wasn’t a consideration, & dry/“real” air conditioning is wealthy homes. But most places? Were built to manage the heat (vaulted ceilings, thick walls, wide windows), OR not meant to spend time in / sleeping outside even, in addition to living mostly out of doors. Ditto, local culture meant a lot of getting wet at least a few times a day to cool off. When it’s 95F/35C to 105F/40C out for months at a time? With spikes of up to 125F/50C? Cultures accommodate for water. Even in the Middle East… Abayas are BLISSFUL rather than constricting, IME. As they billow around and create your own private little windstorm blowing on you. Loved that. I was far hotter wearing far fewer clothes.
Where I live now (Pacific Northwest) the temp is 50F/10C nearly year round… so air conditioning is very rare.