For more extreme winter conditions, level up to Smartwool’s 250 GSM merino wool base layers. Wool and silk ... s hard to do better than Uniqlo’s affordable, effective Heattech line.

Like the socks this brand built its reputation on, the Smartwool Merino 150 base layer uses Merino wool – a material that's often used for outdoor apparel, being breathable yet warm, and ...

As someone who loves the winter, I’ve had my fair share of borderline-frostbitten toes, but ever since I discovered the merino wool base layer, I’ve been able to stay out longer than ever.

Fortunately, we’ve got an easy trick to tell which merino wool base layer is right for you. Merino wool base layers, also known as thermal underwear or long underwear, come in various weights ...