It's mostly a matter of stubbornness. Plus your body can get used to a lot of things if you let it. Probably overnight it would get down to around 80F as well.
Today its about 65F, which is quite pleasant. I've found it makes me appreciate these days more.
Everyone is different, but I can’t imagine anything remotely comfortable about sleeping in 90° heat with high humidity. Having recently had to spend a few weeks “sleeping” (more like constant restlessness) in a bedroom in the lower 80s, that just sounds like hell.