Wool wicks. So most of my dogsledding and outdoor garb is always wool. Even though you are recommended not to, I wore cotton under my wool socks and upperwear. If I did not wear cotton, I wore silk, as it does keep you warm. I did not believe it at first, but the old-timers had me try it, and sure enough the silk worked as well as my Patagonian gear.
I wear jeans under my WWII wool army pants, and never was cold at -40c
Cedar