Although all climbers are well aware of having suffered from numb cold feet or hands for hours at a time with no ill effects, it is important to realise that while being frost-bitten the subject is senses no more than this familiar numbness. Clip one on your sack. In early or superficial frostbite in the unthawed state the skin is yellowy-grey, painless, numb and leathery to the touch.
Pain occurs as rewarming takes place.
In deep frostbite the tissue is hard, white and obviously frozen, like a piece of chicken from a freezer. If the feet are frost-bitten the difficult decision has to be made about the patient moving on foot. There are no absolute rules but in general it is better to move for six hours with frozen feet to a place of safety than to thaw the feet at a high camp. Walking on vulnerable inflamed unfrozen tissue can cause further injury. Once safe, rewarming should begin without delay.