Searched: Any combination of terms to do with hypothermia and sex, but apart from a lot of fiction I'm not really finding the medical stuff I need. This book helped, but I'm not sure if I completely understand what it's saying.
So, I have two (precariously) romantically-linked medical professionals trapped in a storage room (which is empty) (and is structurally composed of ice and snow a la sundry Ice Hotels). Both of them have cold-weather gear on but have no medical supplies, and they'll be there for hours if not a full day or two. I'm pretty happy with my research on the actual effects of hypothermia, I think I've got that down pat, but what I have a bigger problem with is: how feasible is it that they would resort to having sex to keep warm? How long would it take, probably, for them to reach that step? What kind of, you know, practical/technical issues should I be concerned about? Anything you've got to offer on the subject would be so useful.
EDIT: Thanks, guys! Your comments have all been helpful and since it doesn't actually hurt the story for them to not have sex at this point I'm going in a different direction with the scene. Problem solved!