Super comfy, super warm. The flannel is thin, but it holds in heat so well. I spend a lot of time in the basement where my gaming systems are set up and it can get pretty chilly down there but with these I don't even have to bundle up in a blanket like I used to. Only complaint is they are a little long, I'm 5'10" and have to roll the cuffs on the legs a little bit to avoid walking on them all the time.