From L'Amour's Last of the Breed:
Advice given to an older man (in his seventies) and his young daughter who are trying to escape on how they travel the mountain-"Do not think of time. Short marches are best for you. Camp early, so you can be snugged in well before dark. In the darkness you can find nothing. Start early but do not exhaust yourselves. Most people who freeze do so only because they have burned up their stores of energy before stopping to rest and have nothing left to fight the cold. Do not become exhausted."
It sounds so familiar.