We had window unit A/C in our very-poorly-insulated 100 year old farmhouse, when I was growing up and money was very tight, as in if we go shopping and eat out, you're getting water to drink, sharing a meal, and no dessert. Not like starvation levels of poverty but still, money was tight. A/C was not considered optional, even if you could theoretically remain alive when the temperature was over 100F every day for weeks straight and stayed in the 80s (or even 90s) at night.