lesson learned for me.  I probably would have walked away at some point.  my rule of thumb was that serious CPR is only worthwhile for drownings and electrocutions.  I guess i'll add hypothermia to the list  :-)
Pete 
Since nobody mentioned the obvious yet, I will.  Her being gorgeous and alone had something to do with their continued efforts.  She was like the dazzling damsel in distress.  I guarantee at least one of the guys (or girls) had previously fantasized about her being his (or her) future wife.