I take it you've never lived in Texas.

Triple digits and high humidity are the norm for some parts of summer in some parts of Texas. No, opening a window isn't a fix.

People are responding pointing out that there are lots of places where it's too hot for this -- but actually, I do live somewhere this would work, except that the condo I live in has tiny slivers of barely-openable windows (I think it's because of the environmental certification the building got?) that don't let a meaningful amount of air in or out. All the heat from lower floors traveling up also then means there are times we have to run the AC in winter... thanks, architects.

When I was a kid growing up in Central Texas we didn't have air conditioning. In the summer we did sleep with the windows and the exterior doors open. There were screens on the windows and at the exterior doors for air circulation. You could sleep well with a lightweight sheet. Being young and being accustomed to spending all the time outdoors that I was allowed, I was totally acclimated to the situation. The worst part of all that were mosquitoes and chiggers in the summer. Once the nights became cool enough to require a blanket we kept the windows closed until things started to warm again in March or April. We had a gas floor furnace that heated the house. On the coldest days all of us could be found in the living room where the floor furnace was located.

By the time I was a teenager we had moved into a house with window units for AC and central heating.

Anything is doable if you are prepared. I suspect a lot of people today have become acclimated to an unnaturally limited temperature range and therefore they can't handle being outside all day in the direct sun without needing a way to cool down. Same thing in winter. People have acclimated to a range of 65-80 and anything outside that range requires different clothing, moving chilled or heated air, etc.

This ridiculous notion is the surest fire way to tell you’ve never even visited Texas.

In 90F+ weather? (With high humidity most nights!)

Good idea, need to let the hot air in.