Not sure why I'm thinking about it today, this the hottest day of summer so far... But I'm a little concerned about the effects of sitting on a bike saddle in extreme cold for any length of time (i.e. 2+ hours).

Here is the thing: sitting compresses all the clothing layers, squeezing the air out of them, which reduces their ability to insulate as well as their ability to shed moisture. Combine that with the fact that the seat and seat post will act as a heat sink means that the possibility of frostbite in places where you really really do not want frostbite is a major concern.

This is going to be a serious problem to solve...