Getting into hot water as a solution to hypothermia
From BearWiki
Claim: Putting a hypothermic patient into warm water can cause a massive increase in peripheral bloodflow and, ultimately, death.
Warming up a hypothermic patient is almost always good, so long as you take care not to burn them. Warm water bottles, electric blankets, forced air warmers, and so on are all good ideas. The one big exception is exactly what Bear sought out: hot water (in his case, a hot spring). Putting a hypothermic patient into hot water can, quite simply, kill them.[1]. You should never put a hypothermic patient into hot water. This can cause a massive increase in peripheral vasodilation, cardiovascular instability, and ventricular fibrillation.
Hypothermia is not the immediate, major threat that it is often made out to be. Hypothermia is not a disease, syndrome, or absolute emergency[2], but your body taking exactly the right steps to recover from reduced core temperature: cutting bloodflow to the extremities to reduce core heat loss and burning blood sugar as fast as it can (through shivering) to warm the body up. Once the cause for the reduction in core temperature is alleviated, the body will almost always warm up on its own, so long as blood sugar levels are kept up (sickly-sweet fluids are advisable[3]).
