Icebreaker is the perfect clothing for anyone who moves in the outdoors. I wore a single lightweight long sleeve shirt for a week long mountain biking trip from Telluride to Moab, and it kept me comfortable in temperatures from 50-90F, blocked the sun, and didn't hold any odor for the entire week! The Rock Zip does the exact same thing in a slightly different temperature range. 30-65F, depending on how you layer. I carry less clothing on multi-days than ever, because two layers of Icebreaker and a shell cover such a wide range of conditions. I gave away all my miracle fabrics two years ago and will never wear them again.