I've been pleasantly surprised at how much I have acclimated to cold. I HATE feeling cold but I've really built up the ability to heat my core riding the bike. Saturday was unpleasant because I never got out for a real ride so I never warmed up - so eventhough I hadn't gotten into the cold, I felt colder than the days where I'm out in 11 below! My fingers were blue and I went to the warmest room in the house and cranked the space heater... whereas if I get out and do a ride, with a million layers, and keep the energy level up... I'm warm. But the layers only insulate the heat I make, so I have to get moving to make it...