I got out for three days in the Boundary Waters this last week-end and gave my new Alpine Light jacket its first real test. Man is it warm! Standing around in the teens and upper single digits, I had to keep it partially unzipped to stay cool enough. The rest of my clothing included a turtle fur balaclava, omni wool long underwear top and bottoms, poly zip-t shirt, poly pants, wool socks, mukluks, and liner gloves. Love this jacket. Very light, very warm, and fits well.