






Wool Thermo Light T-Shirt Base Layer - Women's
Built to keep you dry, warm, and moving through cold, high-output conditions.

Lightweight Merino comfort with airflow built into every layer.
Wool Thermo Light uses soft, superfine Merino in a finer mesh that feels lighter and looks more conventional than Brynje’s larger-cell wool mesh. It balances warmth, airflow, and natural odor control for daily wear, shoulder-season conditions, and active use where there is less risk of extreme cold.
35°F to 60°F
2°C to 16°CA practical starting window for daily wear and medium-output activity in cool to moderate conditions. Wool Thermo Light is designed for spring, summer, and fall use, or colder conditions beneath a complete layering system. For sustained high exertion or greater moisture transport, Super Thermo may be the better next-to-skin choice.
Temperature windows are approximate, not safety ratings. Wool Thermo Light is best selected by activity level and the complete layering system. Comfort varies with metabolism, pace, wind, humidity, precipitation, altitude, and duration.
Find Your Perfect Fit
Why Fine Merino Mesh Works
Wool Thermo Light uses a finer Merino mesh to create airflow and insulating space with a smoother, more conventional appearance. The smaller cells reduce fabric contact with the skin, move excess heat and moisture outward, and hold warm air when activity slows.
Performance Layering Mechanics
Toggle between the modes below to see how the mesh manages moisture and warmth.





