Adventure all day in the cold with the enhanced breathability of the men's Smartwool Intraknit Thermal Merino Colorblock Crew base layer top, designed with body-mapped mesh and distinctive patterning.

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Keep your temperature just right on cold days with the built-in ventilation of the men's Smartwool Intraknit Thermal Merino Colorblock Quarter-Zip base layer top featuring body-mapped mesh zones.

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Keep your temperature just right on cold days with the built-in ventilation of the women's Smartwool Intraknit Thermal Merino Colorblock Quarter-Zip base layer top featuring body-mapped mesh zones.

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This minimalist Smartwool Intraknit Thermal Merino crew base layer top is anything but insignificant. It's a lightweight, super-moveable top perfect for all of your sweatiest cold-weather activities.

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This minimalist Smartwool Intraknit Thermal Merino women's crew base layer top is lightweight and super-moveable—perfect for all of your sweatiest cold-weather activities.

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Whether you're skiing, ice-fishing or snowmobiling, set the tone for all-day comfort with the body-mapped mesh vents of the men's Smartwool Intraknit Thermal Merino Half-Zip base layer hoodie.

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Highlight your base-layer comfort in floral. The women's Smartwool Intraknit Thermal Merino Pattern crew top is designed with targeted mesh-ventilation and a 3D-mapped fit to venture through the day.

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Engineered to enhance performance and maximize mobility, the men's Smartwool Intraknit Thermal Merino Quarter-Zip base layer is durable and warm yet lightweight and easy to layer thanks to a slim fit.

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A good choice for cool-weather adventures, the women's Smartwool Intraknit Thermal Merino quarter-zip base layer top helps keep your body dry and comfortable—and the fit won't slow you down.

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Made of 100% merino wool, the Wild Rye Jane 7/8 Crop leggings are built to endure the rigors of long days in the mountains. They're cozy enough for apres, but technical enough for weeklong hut trips.

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A lightweight base layer with a shortened silhouette, the women's Wild Rye Jane Lite crop leggings will keep you warm (but not too warm) from spring skiing to summer camping.

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Bike-riding kids are just as concerned about comfort as their parents. The Zoic Kids Komfy bike short liners feature a mesh spandex shell with molded foam chamois pad to keep them happy in the saddle.

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Looking for a base layer legging with a sleek, soft design? The women's Kari Traa Klara high-waist base layer pant has a slim silhouette with an extra-high, extra-comfy waist for added coverage.

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Combining a warm, breathable 100% merino wool exterior with a 100% LIFA® wicking interior, the Helly Hansen LIFA Merino Midweight Graphic pants are the perfect base layer for cold-weather pursuits.

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