As was stated, make sure your boots are not too tight, that alone will impede circulation in your fet making them cold. Wear a polypro typw sock under your heavier socks to allow the moisture to wick away from your feet. Thay make foot warmers that stick to the bttom of your socks but I have no idea if they work, they also make electric socks that are supposed to be better than the old style, again, I didn;t ever use them, I know the old ones were pretty much worthless.