Men's & Women's Thermal Base Layers
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Classic Thermal Collection
Discover the Classic Thermal collection, Smartwool’s warmest and most versatile line of base layers, designed to keep you comfortable in the coldest conditions. Made from 100% Merino wool, the thermal collection is incredibly soft, warm, and breathable, providing superior insulation and moisture management. Whether you're skiing and snowboarding, hiking, or simply layering up for a chilly day, the Merino 250 collection is your go-to for all your cold-weather needs.
Our base layers are perfect for both active and casual wear, offering excellent stretch and recovery to move with you, while flatlock seams minimize chafing and provide all-day comfort. Available in a variety of styles for men and women, the Classic Thermal collection is designed to fit all body types and preferences, ensuring everyone can enjoy the benefits of Merino wool in the coldest temperatures.
Our commitment to quality and sustainability means our Merino garments are not only high-performing but also responsibly made. Our wool is ethically sourced from sheep that are well-cared for, and our environmentally friendly manufacturing practices ensure that every piece is crafted with care for the planet.
Want to shop locally? Smartwool products are available at over 5,000 stores across the U.S. Use our Store Locator tool to find a location near you.
Classic Thermal Clothing FAQs
Q: What makes the Classic Thermal collection ideal for cold weather?
A: The Merino 250 collection is crafted from 100% Merino wool, which provides exceptional insulation while remaining breathable. The fabric's natural crimp traps heat effectively, making it perfect for cold-weather activities. Additionally, Merino wool naturally wicks moisture away from the skin, keeping you dry and comfortable even when you’re working up a sweat in chilly conditions.
Q: How do classic thermals compare to other base layers in terms of warmth and weight?
A: Merino 250 is Smartwool’s warmest base layer, offering more insulation than our lighter-weight options. It provides superior warmth without adding bulk, making it ideal for layering under jackets. The 250 weight designation refers to the fabric’s density (grams per square meter), which is perfect for cold weather where maximum warmth is needed.
Q: Can I wear a classic thermal as a standalone piece, or is it only for layering?
A: While Merino 250 pieces are designed primarily as base layers, they are stylish and comfortable enough to be worn on their own. The fabric’s softness and natural stretch make it suitable for wearing as a standalone top during cool-weather activities or casual outings.
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