Keep Them Warm and Toasty! Winters can get rough and cold. These thermal long johns will help you make it through They are silky on the outside but lined with soft thermal fleece on the inside. They fit snug enough that there is no bulkiness showing when worn under clothes. They are also wonderful to sleep in. These sets will continue warming you even after being laundered many times. These Rocky Fleece Lined Thermals are well designed to wear under your clothes or alone.