Our WARMEST Coldpruf winter thermals. Be prepared for the worst with our Coldpruf Extreme Performance expedition weight long underwear. These are guaranteed to keep you warm in any conditions. Engineered for extreme cold temperatures, the 360 degree stretch not only provides a snug comfortable form fit, it also maximizes the thermal fabrics ability to trap heat next to your body so you stay warmer. We recommend these for colder days on the ski slopes, hunting, fishing, cold weather touring or cruises, or for anyone who get's cold easily. You'll love the luxuriously soft feel of these high performance expedition weight long johns.