Arc'teryx Phase SV Hooded Top - Women's - $23.69

You dream of finding the ideal base layer for aerobic stop-and-go activity on frigid alpine days, but it never occurred to you that this very shirt could also be a hoody. Fortunately, Arc'teryx's designers dreamed up the Women's Phase SV Hooded top. It boasts supreme moisture management so you don't get a case of sweaty shivers when the wind kicks up, it stretches like a champ, and it features silver-ion fibers for built-in odor control. A sleek, smooth outer face glides under your other layers and a fuzzy interior provides plush insulation. - $23.69