During my stint in the Army I was stationed in south korea. The winter there was super cold. We were issued "bear suits" (heavy fleece overalls) and "mickey mouse" boots (rubber inflateable boots)

The problem was that not only would you sweat like you cant imagine in that stuff, you also had roughly the same appearance and mobility of Ralphie's little brother in "A Christmas Story".

I had my father ship me a set of silk long johns and battery powered socks. Man, It was like night and day!! I had no idea that silk kept you that warm and felt so nice. No sweating, no bunching and could be worn under bdu's with no "fat feeling" like the polypropeline issue long johns .

Silk, all the way..