I wear synthetic trunks, same for socks, not wool etc... but a polypro wicking sock. Wools are in the foot bed just in case though and to dry out, inside out....
I always have some type of head gear on. As we are much more used to ( I never said enjoy...) 110 degrees, than anything under freezing, its often a full face balaclava type deal.
Always wanted to order one of those sleeping bag head/hood setups I've seen but never have...