Harvey,
When I go out in the winter and come home spent. It is not unusual for me to have problems getting warm, even with the thermostat set at 70* F, with a R2 vest on and being under a blanket, until I spend 15 minutes in a hot shower...this after having 15+* F to 30* F plus wind for hours without a problem.
Going out in winter teaches you so much more about hiking.
