Having read the current crop of posts, and following on my answer to Jbee on yoga, it put me in mind that I hadn't yoged since Monday so I went out naked for a bit of yoga to test my resilience on a day that was broadly uninviting for outdoor nudity.
Cloudy, 70% RH, 6mph wind and 51°F, so a bit damp and dreary.
I didn't feel particularly chilled, my feet were 'positively' cold on the flagstones i.e. fully functional, no pain from the cold. However, I only did a few minutes slow, standing asanas before my upper body was suggesting I go back inside. It wasn't majorly uncomfortable, just less than comfortable. Didn't get much of a workout!
John