During the Dark Ages when knights would dawn their majestic armor, they would wear cotton robes underneath for comfort. The same basic concept has been adopted today when snowboarders don baselayers to keep them warm. For a baselayer that will keep you warmer than the Mexican Riviera, check out the 686 Rings Base Layer Top.
92% Polyester / 8% Lycra "Toptech" jersey knit face with bonded brushed microfleece inside
Toptech The heaviest weight of 686's technical base layer garments with 330 g insulation
Antimicrobial finish to guard against odor causing bacteria/fungi
30+ UPF guard