I tried the SmartWool 250's this week during opening deer rifle season. I like them. As others mentioned above, today's merino wool is not your grandpappy's wool. The reason why is because of they way they process wool today: they separate the course outer sheath of the wool fibers (that's what scratched and itched in the past). The SmartWool 250's are very warm. In fact, down to the 40's, I am comfortable wearing just the SmartWool 250 crew top with no jacket. In the 30's, I'll want to throw on a good jacket on top of the top layer, but I am very impressed with the performance of the SmartWool 250 gear. Plus wool wicks sweat and keeps you warm even if you get wet (in the rain, for example).