I spent my time from age 32-37 exercising outdoors year round regardless of the temperature (in that area, down to 25F for January/February). My body quickly adapted to the colder weather as the seasons changed, and my only change in attire was to go from a short sleeve t-shirt to a long sleeve t-shirt. This year, I've spent almost no time outside since the summer (injury ended my running for a bit) and the winter temperatures are cutting through me (also it's colder here than my previous home, but not so cold as to fully explain the change in my comfort with it). When I wasn't exercising, I found that light (but long sleeve/long pants) clothing was sufficient nearly any time I was outdoors in the winter, even when traveling to much colder places (like the mountains for my friends' annual ski trip).

Being indoors in consistent temperatures eats away (or does for me) our ability to adapt to temperature changes. I'm planning to start doing some walks to try and get myself adapted better to these temperatures, and next year plan to spend more time outdoors through the fall (in particular) so that my body properly adapts to the next winter.

Honestly, I think that's part of the cause of my problem. For 9 years I spent one weekend outside every month, summer or winter, rain or shine. (Military reserves.) My feet spent a lot of time hovering just above frostbite level. I think the speed with which my body cuts circulation to my feet is probably a learned adaptation from that time period.

I'm interested in the idea of running barefoot, could you share a reference or two?