Smartwool Classic Thermal Merino Base Layer Crew – Kids' race-day Its breathable groove design prevents

Its breathable groove design prevents heat and moisture buildup during workouts

Cyclone construction wraps recycled synthetic insulation in vertical baffles for efficient heat retention

Ribbed knit cuffs and hem seal out drafts and hold their shape over time — available in Rust/Copper Brown for a classic fall colorway

Lightweight and packable enough to toss in a bag for travel or a weekend trip

Smartwool Classic Thermal Merino Base Layer Crew – Kids' race-day Its breathable groove design preventsBuilt for active kids who won't slow down when the temperature drops, the Classic Thermal Merino Base Layer Crew is our top pick for cold weather layering. Merino wool naturally regulates body temperature and resists odor, so they stay comfortable from first chair to last run. Flatlock seams cut down on chafing during all day movement. Merino wool construction provides natural warmth without bulk regulates temperature as activity levels change