Conquer unpredictable shoulder season weather with these Merino wool base layers.

By trapping heat and wicking away sweat, the best base layers are a cheat code to staying warm when you bundle up, so we tested 15 and found three winners.

There’s no doubt that merino wool is an insulating rockstar among outdoorsmen and women. Thanks to its warmth, breathability, moisture-wicking, and odor-repelling performance, it has a massive fan ...