Hypothermia (IIRC) is a result of your bodies inability to maintain internal temperature. Your body maintains internal temperature by burning fuel (eating). I am no Doctor or Medic but when I had hypothermia I managed to get into a tent and bag and still couldn't stop shaking. With great difficulty I was able to heat a quart of water, make powdered chocolat milk and drink it down. Because it was warm? Because it was fuel for my metabolism? I think a little of both.

Jon