The Patagonia Capilene Thermal Weight Men's Zip Neck is a proper cold-weather baselayer top, the kind you live in from December through March. Its grid-fleece interior banks warmth while the zip neck lets you vent on the climb, and it layers easily under any midlayer or shell.

Why we like it:

That deep zipper is the everyday hero, opening up fast when you overheat and sealing to the chin when the wind picks up.

Features and Functions:

The base is Polartec Power Grid at 4.5 ounce, a 92 percent recycled polyester and 8 percent spandex grid fleece that insulates through trapped air and vents heat through its channeled back, all treated with HeiQ Mint odor control. The zip neck has a wind flap behind the zipper, offset shoulder seams reduce pack chafe, and the top comes from a Fair Trade Certified factory.

Fit and Sizing:

It has a slim, athletic cut meant to sit under other layers, and it fits true. Between sizes, go with the smaller for a trimmer feel.

Bottom Line:

This is your midwinter workhorse for resort days, backcountry tours and any cold outing where you want adjustable warmth. Skiers who like a versatile, insulating base will reach for it constantly.