I second every word that elace3733 said. it is quite bizarre how a piece of garment can be so sophisticated and just plain good! The second you put it on you feel the warmth your body generates. When you body transits from stone cold into defrosted stage after you pedaled for a while, or maybe if sun came out, there is a brief moment, that you feel like you are starting to sweat, but a minute later the body regulates and it just feels perfect. I actually like these so much I have 4 of them and using it also at home sometimes when it is cold.