Having lived in northern BC, and as well having commercial fished in manky weather, I've learned to always start with my feet...if my feet are warm, dry, and comfortable, that's a good start. If feet, head, and hands are comfortable, that's over 50% of the battle right there.

It's noteworthy that the Inuit in the high arctic traditionally wore high boots and a parka that was open at the bottom, and it was rather like being in a bell. They knew the importance of ventilation, and for them sweating often spelled death.