So any time you begin shivering due to cold you are on the edge of hypothermia ?
I guess its because I have to understand there is degree involved .
I wrote this for another outdoor web site but I'll post it here. Hopefully this helps a little.
What makes hypothermia so insidious is how we tend to ignore it and misidentify it. By
definition hypothermia is a lowering of your core body temperature from what is normal. The thing to keep in mind is that all your bodies reactions with respect to hypothermia is
core driven. By that I mean, you cannot put your hand on a piece of ice and that alone will cause you to shiver. You might give yourself frostbite but the only way you start shivering is if your core temperature has dropped sufficiently. Shivering
is one of the first signs of hypothermia. I have been taught that actually the first is a mental degradation. I know this will sound corny but follow this through. A group of people standing around. One guy standing there shivering and the other says “you look cold?” The guy says “Yeah, its freaking cold out man”. The other says “why don’t you put your hat on?” The shivering guy says “NO I’M OK”. Anyone seen this happen? I know I have. Hell, I’ve done it. Fact is. He is not OK. He is already got a core temperature low enough that his body is responding. It is responding by shivering. This shivering is your bodies way of making your muscles generate heat. This is how the body responds to hypothermia in its first stages. This is when to treat it but his mental degradation is telling him, “NO I’M OK”. He doesn’t recognize how much trouble he is in. This is more than just a warning sign. It is actual hypothermia. It’s just that we see it and ignore it so often many of us don’t recognize it as such. Are you going to die in minutes, hours? This obviously depends on the conditions, but make no mistake you are headed in that direction.
From there of course it goes downhill. You experience a loss of fine motor control so you find it harder to tie your shoes, change your wet jacket and other simple tasks. This is directly attributable to your extremities being vasoconstricted and shunted, again, core driven. Your hand muscles are receiving less blood so they cannot perform the way they normally do and the way you think they should be performing. Everything takes longer to do and is more of a challenge. Yes you can stop your shivering at this stage (first stage) by force of will.
You are in stage two when you have a loss of gross muscle coordination and at this point you cannot stop shivering. You also suffer from the ‘umbles. They are still conscious but will st
umble when they walk, m
umble when they talk, and f
umble when they attempt to do simple things. You are getting near the point of no return.
End stage consists of unconsciousness and shivering has stopped. The body cannot re-warm itself at this point. It is almost impossible to help someone in the field to bring them back to consciousness. The best you can do is to try to keep them from losing more body heat. Change them out of wet clothes, put them in dry clothes and put them in a hypothermia wrap and evacuate them rapidly and treat them very gently.
One other statistic I will leave you with is that any person, who has a core temperature change (up or down) of seven degrees, has a 50/50 chance of surviving.
A second posting to that same website by me.
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 by warming an arm or two you can have a very severe adverse effect by placing someone into a tub of warm or hot water.
KR
NREMT-B
CT EMT-D
Wilderness EMT
