My apartment has 30 windows, and at the moment all 28 of the ones I can reach are open. But the temperature keeps ticking up. Right now my office is a comfortable 25°C with a gentle breeze passing through. The Nest sensor in my bedroom reads 23°C, also a lovely temperature for the end of September.
Tonight, however, I would like to sleep, and at 23°C I feel too warm to sleep well. I prefer it around, oh, 17-18°C. I can do all right at 21°C.
So: do I wait for the temperature to fall naturally after the sun goes down in a bit less than three hours? Or do I hit the A/C? The NWS says it'll be 21°C by 11pm and 17°C right before sunrise.
See? My ancestors didn't have to think about this when they wandered the savannahs of Africa 100,000 years ago. They just had to worry about lions.