I always boggled at why some students would wear shorts all year round in a "just-about-as-cold" area of Wisconsin. You were walking across campus for 10-20 minutes to get to class. Why not be comfortable.

Strangely, with my Scottish heritage, I get wearing shorts in cold weather. Physiologically, as long as the head, trunk, hands and feet are warm, insulation for the rest of the body doesn't matter that much, especially if you're walking somewhere and generating heat.

Within reason. :)