Streamlined, lightweight and warm, the men's Janji Mercury track pants are a go-to for cold weather runs. Plus, they come with 3 large pockets that keep all your must-haves handy on the move.

Pants ParentPants

Soft, breathable and naturally odor resistant, the ultrafine merino wool of the men's REI Co-op Merino 185 base layer bottoms is just as beloved while sweating on the trail as sleeping in the tent.

Underwear BottomsBase Layer Bottoms

Soft, breathable and naturally odor resistant, the ultrafine merino wool of the men's REI Co-op Merino 185 base layer bottoms is beloved for sweating on the trail—and just sleeping!

Underwear BottomsBase Layer Bottoms

Hike, bike and even sleep in the men's REI Co-op Merino 185 short-sleeve base layer top. The soft, breathable and naturally odor-resistant ultrafine merino wool makes it an ideal next-to-skin layer.

Underwear TopsBase Layer Tops

Soft, breathable and naturally odor resistant, the ultrafine merino wool of the men's REI Co-op Merino 185 long-sleeve base layer top is beloved while sweating on the trail—and sleeping in the tent.

Underwear TopsBase Layer Tops

Soft, breathable and naturally odor resistant, the ultrafine merino wool of the men's REI Co-op Merino 185 long-sleeve base layer top is beloved for both sweating on the trail and just sleeping.

Underwear TopsBase Layer Tops

Soft and breathable, the ultrafine merino wool of the naturally odor-resistant men's REI Co-op Merino 185 long-sleeve half-zip base layer top is ideal for sweating on the trail—and sleeping in a tent.

Underwear TopsBase Layer Tops

The ultrafine merino wool of the men's REI Co-op Merino 185 long-sleeve half-zip base layer top is an ideal soft, breathable, odor-resistant layer for sweating on the trail—and sleeping in a tent.

Underwear TopsBase Layer Tops

Built with soft merino, the Icebreaker Merino 200 Sonebula Long-Sleeve High-Neck Thermal top regulates body temperature in all weather conditions while resisting odors. High collar adds coverage.

Underwear TopsBase Layer Tops

When you're out in the backcountry and your hands need some backup, make sure to bring along the Smartwool Merino 250 gloves on your next outdoor adventure to add extra warmth under your shell gloves.

Gloves and MittensWarm Gloves and Mittens

Keeping your neck warm and dry helps you stay comfortable in cold, harsh conditions. The Smartwool Merino 250 neck gaiter is made from NTS Midweight merino wool for a soft, comfy feel.

HeadwearNeck Gaiters

Made from fabric developed exclusively by Rapha, the Rapha Merino arm warmers combine the natural performance properties of merino wool with a degree of Lycra® spandex for stretch and durability.

WarmersArm Warmers

Stay dry on the trail in the soft, breathable and naturally odor-resistant REI Co-op Merino Boxer Brief Underwear for men. They're made to keep you comfy throughout the day.

UnderwearUnderwear Bottoms

Stay dry on the trail in the soft, breathable and naturally odor-resistant REI Co-op Merino Boxers for men. They're made to keep you comfy throughout the day.

UnderwearUnderwear Bottoms