Alsatian

I have used polypropolene long underwear and long sleeved shirts for many years -- since 1984. When deer hunting I usually wear polypropolene as my first layer. I find it keeps me dry and has never made me uncomfortable. My polypropolene is old -- purchased in 1984 -- and feels a little scratchy next to my skin: this is the only discomfort I have ever felt RE polypropolene. Maybe the technology has improved in the last 20 years and polypropolene avoids this scratchy feeling, but it hasn't been something that deterred me from using this very successful technology.

I'm planning a hunting trip for mid October at about 11,000' in the Southern Colorado rocky mountains and I'm looking to get something a bit warmer as this first layer. I don't know if that will be expedition weight polypropolene of some other synthetic fiber that wicks moisture effectively.