[Beginning of Rant]
i just want to go on record as a normal person here and state that all you guys going without ac where its hitting 90 are NUTS and if youre sleeping in an 80 degree room, you need help; 80 is beach temperature not sleeping temperature.
room temperature is 72 qnd generally considered the maximum temperature during sleep at my house. if it takes an extra year to become fi because of my ac expemses, i am quite okay with it. hot and sweaty is not an acceptable state of being in a 1st world country.
[End of Rant]
A lot of it is how you are conditioned.
If you are used to working in an office and living in a house chilled like a meat locker, 80 degrees seems unbearable.
If you ween yourself off the fossil fuel burning, high cost artificial air, it's not a big deal.
As a side bonus, if you ween yourself off the artificial air, you won't break out in a sweat every time the temp goes above 75.
We usually keep our AC at 79 or 80, and that's only because my wife is a soft, weak and whiny city girl. If it was up to me, I'd be fine up to 83.