Shivering

[rambler]

In Scott's diaries found on his body near the South Pole, he describes knowing he was cold because his skin had stopped shivering, but his bones were shaking.

 

[SAR-EMT40]

The blood in one's extremities can be signifcantly cooler that the core. If the cooled blood is rapidly circulated into the core, it can result in a fast core temp drop and a rapid onset of hypothermia.

This can be an issue in rewarming a chilled victim.

Doug

This really can't be a problem with external warming unless someone is actually placed in a tub of warm/hot water.

I believe what is being referred to is “afterdrop”. This is a phenomenon that occurs as the vasoconstriction and shunting in the extremities begins to be relieved because the core temperature is rising. Then this cold blood starts to get back into the core and the cores temperature drops (usually slightly) again. This is rarely serious.

There has been tests done and just heating the extremities can not cause the flood of chilled blood back into the core. More importantly, the temperature of the blood isn’t as big a problem as is the fact that the blood is usually loaded with nasty by-products from the effects of long term anaerobic cell activity which can definitely affect the heart rhythm or even cease it. If you are vasoconstricted and shunted in the extremities then you are already hypothermic, by definition. This vasoconstriction and shunting is core temperature driven meaning your core temperature determines if your extremities are vasoconstricted and shunted, not your extremities.

Never place a severely hypothermic person in a tub of warm water. While you cannot cause any real effect (good or otherwise) by warming an arm or two or four you can have a very severe adverse effect by placing someone into a tub of warm or hot water and making them vasodilate very rapidly.

Keith