Fleece-Lined Joggers

Fleece lining means the inner face of the knit has been brushed into a soft pile while the outer face stays flat, which is a two-sided fabric doing two different jobs at once. The raised inside traps a layer of air against the skin and is what makes these noticeably warmer than the same weight of unbrushed cloth; the smooth outside keeps them looking like regular pants rather than like thermal wear. Wash them inside out and skip the dryer, since heat and agitation are what mat the pile down and take the warmth with it.