any chance you're feet are sweating and you're getting cold from that? That was my issue. I've been wearing a light wool sock, nearly every day in the winter. They wick sweat and keep your feet warm anyway. In cold or hunting situation, I throw a medium or a heavy wool over the light wool/smart-wool blend that is on my skin.
It works great. I've been a much happier hunter the last few years since I've found the right combo of socks/boots.
