Posted on behalf of Prof. Mike Tipton (University of Portsmouth):
Predicting cold exposure survival time on land is a very inexact science. The Cold Exposure Survival Model (CESM) (written by Dr Peter Tikuisis) can, I believe, be used for land predictions, but without knowing much about the circumstances of an accident, it will have very wide confidence limits.
For interest I have attached a few of our papers/chapters on this area with respect to water - the variability on land is greater!
All the best,