I have to agree that under armour is the way to go. it can be kind of spendy but its worth every last cent. i wore my old one and my new one at the same time this yr and only had on a hooded sweatshirt over top of them and i didnt get cold one time. we were hunting in about zero degree temps. every time too. It really helps wick away all moisture and like already said, you cant tell that you have it on. its not bulky in any way shape or form.