Military Thermal Underwear is genuine US military-issued thermal underwear -- simply the best cold weather Underwear you can buy. Made from polypropylene, this underwear keep you warm without allowing moisture to accumulate. Our Thermal Underwear is great for cold weather outdoor activity like off roading, snowmobiles, or ATV's, hunting, fishing, camping, skiing, or for just taking the chill off a cold office. Let the cold weather technology of Our Military Thermal Underwear go to work for you.