Was out in 34 degree weather (warmed up to 45) today..just got these 2 days ago and I had a smile on my face when I got these from the Post Office! Man, my legs never got cold- at all! I  had thick socks so my doggs were warm also! Glad these are made from Poly-if you get them wet-they will still keep you warm! Never use cotton longjohns or cotton thermals because once wet, you're miserable. I got 6 pair of these and I may get 2 more pair! If you work outside or do alot outside and want a great thermal underwear--this is it! Like one gentleman wrote-don't throw in dryer! I would say launder in warm water-then air dry!