These are the best base layer pants. I’ve tried many types of synthetic base layers that have left me either cold, or so hot that I sweat like crazy. I wore these under my pants around the campfire while camping and I was toasty warm. The real test came that night in my tent. The temp was cold, cold, cold, but for the first time ever, I stayed warm without sweating in my sleeping bag. I’m a believer in the magic of merino!