> we haven't been running AC in the summers, so our house has been up around 90F with high humidity. It is very comfortable across that whole spectrum.
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.
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.
What do you wear inside in the winter?
Usually a t-shirt, long sleeve thermal shirt, and a button down shirt on top, then jeans on bottom. Thick socks and probably my slippers for my feet.
I sleep just in my boxers, but we put another italian officers blanket and a thick quilt on our bed to keep things toasty.
As far as heat, we're of the opinion that wool is basically the ideal material. It is breathable, but it matches your body temperature and maintains it pretty well. It wicks the moisture away from you really well.
I don't know how exactly to compare it to other mattresses, but we keep our house at ~60F in the winter and we haven't been running AC in the summers, so our house has been up around 90F with high humidity. It is very comfortable across that whole spectrum.
If you've ever had a pair of high quality wool socks, it's kind of like that. They keep you warm in the winter and keep your feet comfortable and dry in the summer.