The first sentence is a good question, the last sentence is unnecessary snark. I think there are two main things at play: buildings used to be built differentl

The first sentence is a good question, the last sentence is unnecessary snark. I think there are two main things at play: buildings used to be built differently, and yes, people prefer not to suffer these days. Old Australian buildings (e.g. "Queenslanders") were often built on poles to let the air circulate underneath, they'd have the roof extend far over windows to stop sunlight (and heat) getting in. Those are not the most enjoyable places to live in, these days people prefer a bit of sunlight during the day, and a constant draft is not pleasant in winter. And yes, I imagine people just didn't sleep all that well and spent heatwaves sitting around in the coldest spot in the house waiting for it to be over. These days people want to sleep well throughout the year and want to be productive even during heatwaves.