I took the advice of getting a size smaller and it seemed to work out okay. It's a little tight but fine overall. I'm 6'2 and 250 pounds and I chose medium. There must be a lot of big people out there if I wear a medium. I probably would choose large next time for a looser fit.

They are warm, at least for underwear.

I would suggest not wearing them until you wash them. I tried one on out of the package and got a rash.  After washing they were fine.

Would recommend, the price is decent and they do keep me warm.