One word of caution - the "Reusable Heat Pack" from NOLS "Heats up to 130 degrees in 5 seconds."

I'll have to check, but I think this may be too hot for a casualty with hypothermia, especially severe hypothermia. The normal recommendation is to use a heat pad that's fairly close to normal body temperature (e.g. a plastic water bottle filled with a non-hypothermic rescuer's urine). For mild hypothermia, perhaps even moderate, the casualty may be aware enough to realise if the pads start to burn, but if they're semi-conscious or unconscious, you may not know anything's wrong until too late.

With these pads, I would ensure they're at least well-padded, or perhaps even use the "15 minutes on, 15 minutes off" principle (although I've never heard that being recommended for heat, only for ice). In any event, monitor the casualty continuously to make sure they're not overheating - paradoxical as that may sound. <img src="images/graemlins/confused.gif" alt="" />