What could cause cold bare feet to sweat?

Sweaty feet: Feet sweat because the nerves attached to the sweat gland tell the gland to open and excrete its contents. This happens normally. In cases where the feet sweat to much there is ususally a autonomic nerve malfunction.

Hypothalamus: This organ registers your body temperature like a thermostat. Therefore if your hypothalamus is not set properly you can still have cold feet and sweat.