Experience warmth technology in your layering piece with the Fraser Crew. This silk-like, lightweight first layer works alone or under sweaters, flannel, or fleece. The warming factor comes from innovative S° Warm IR reflection technology, featuring ceramic particles in the fibers that provide a thermal boost by reflecting body heat via infrared radiation back to the skin. Add to that the engineered acrylic fibers, which create air pockets that insulate the body and prevent warmth from escaping, and you're ready for any cold weather outdoor pursuits. Patented SILVADUR™ technology delivers silver ions to the fabric surface and activates them in the presence of undesirable bacteria, helping eliminate odor and keeping you fresh for the life of the garment.