Naturally, their thermal underwear follows suit. Made from a premium blend of Merino wool and lyocell, these long johns offer a silky-smooth feel—without the need for a silk budget. Merino wool ...

This natural fiber is one of the best materials for trapping warmth. “My No. 1 recommendation for long underwear is merino wool,” says Sarah Savala, a gear expert and customer-care supervisor ...

Thermal underwear is known by many names — long johns, base layers, long underwear, skivvies, or even britches (for my Southern friends). No matter what you call them, they are a staple for anyone ...