"What Our Gearhead® Experts Are Saying: ""I reach for this on cold days when I want reliable warmth without overheating. The 100% merino manages moisture well during high-output efforts, and the interlock knit feels soft against the skin. The slim fit layers smoothly under midlayers, and the flatlock seams help prevent rubbing on long days.""When winter pursuits demand dependable layering, the Classic Thermal Merino Colorblock Baselayer Crew from Smartwool becomes the piece we build everything around. Whether we’re skinning uphill, hiking frosty trails, or gearing up for a cold morning ride, this crew keeps us dry, warm, and comfortable. Made from 100% merino wool in a soft interlock knit, it naturally manages moisture, regulates temperature, and resists odor through long days of movement. The slim fit contours to the body for efficient layering, while raglan sleeves and forward-wrapped side seams create a distraction-free feel. Finished with flatlock seam construction to minimize chafing, this cold-weather staple is designed to move seamlessly with us through every winter objective."