Okay, this brings up and interesting question...when do you start walking out? James Kim decided to walk out after several days and it killed him but his family stayed put and was later saved (although wikipedia says they were seen by a helicopter pilot while walking down a remote road). While this family was rescued by the last flight since weather was worsening. How long do you sit in the snow cave wondering whether anyone is coming? A week, two? Should you walk out while you're still strong or wait until your body has used up much of its reserves?

For people who've done SAR work, when are search efforts normally called off?