Intraknit Thermal Merino Base Layer Bottom – Women's

For high-output days in the cold — skiing, snowshoeing, or winter hiking — this is our top pick for women who need warmth that doesn't trap heat. Smartwool's Intraknit construction knits mesh ventilation and insulation directly into the fabric in a single pass, so the bottom breathes where you're working hard and holds heat where you need it. The slim, mid-rise fit slides cleanly under ski pants without bunching.

• Intraknit 3D construction integrates ventilation zones and insulation in one seamless knit — no layered panels, no bulk, no hot spots
• 52% merino wool blend naturally regulates temperature, pulls moisture away from skin, and fights odor through long cold-weather days
• Slim, mid-rise cut fits efficiently under ski pants, softshells, or bibs without adding bulk at the waist or thighs
• Built for skiing, snowboarding, winter hiking, and mountaineering — anywhere cold output varies and overheating is a real problem
• Available in Black/White, Emerald/White, and Nightfall Blue/Deep Navy in sizes XS–XXL