This one is for our M.D.s & EMTs. I was emailing with a forum member re: my sleeping bag's rating. It got me to thinking ( dangerous, I know.) I always see victims wrapped in blankets, survival suits, sleeping bags etc. When is the potential insulation to much, or possibly to little? <img src="images/graemlins/confused.gif" alt="" />

I'm not an MD nor EMT, and I don't play one on TV. However, all of my first aid training has instructed to "maintain" body heat. I believe the goal is to keep body temperature "normal." Lots of loft and added heat if the victim is cold, shade and cooling if hot.

I'd be interested to learn of exceptions to that "rule."

/Neal

I think the key would be maintaining the body heat with what every you have, be it a survival blanket, sleeping bag, tarp what ever. This means constant monitoring to check and recheck till the evacuation was completed. This is especially so if your patient/casualty is borderline hypothermic or already hypothermic. This would call for the best insulation available to you plus additional heat sources e.g warm saline, heat packs, fire etc.......

To answer your question, we will only know if it is too much or too little when we check on the temperature on a regular basis.Of course in some cases, too much is better than too little.

<img src="images/graemlins/grin.gif" alt="" />

Your body has 4 times as many cold receptors as it has heat receptors. We have very efficient cooling system but not really the greatest heating system. Increasing circulation when we are cold only cools down body further. Victims you described wrapped in blankets, survival suits, etc most likely experienced some kind of shock. Shock can be due to a number of different mechanisms including not enough blood volume (hypovolemic shock), not enough output of blood by the heart (cardiogenic shock) and of course due to fatigue, death/life situation and exposure.

The signs and symptoms of shock include low blood pressure (hypotension), overbreathing (hyperventilation), a weak rapid pulse, cold clammy grayish-bluish (cyanotic) skin, decreased urine flow (oliguria), and mental changes (a sense of great anxiety and foreboding, confusion and, sometimes, combativeness).

Now in order to treat the above is keeping the victim warm. Preferably IV with warm fluid can be given but if not warm blankets can be used.

Also I was explained that victims who were lost, wondering around they want to have their own space. Giving them a blanket or a bag creates their own space, sort of like a buffer between them and outside conditions that caused them harm.

Is there a danger to overdue it? With typical conscious patient not really. They will strip down or throw the coverings away. If you are performing active rewarming and place a heat pack directly on someone’s body than yes you can cause burns. You have to monitor any unconscious victim assess their breathing and core temperature. But as long as you are just using blankets and they have fresh supply of air available there is not much you can do wrong.


Matt

I can remember both times I went into "serious" shock. Boy was that warm heated room COLD. I RARELY get cold. I was FREEZING, and I was indoors, in the hospital. I can imagine what it's like for someone in a survival situation. Your going to have problems keeping them warm

I can remember them starting the warm IV with morphine. I can also remember them shuttling heated blankets on and off me. I also remember that as soon as the morphine took away the pain, I was OUT like a lightbulb
(Once was a gall stone attack, the other was my first kidney stone attack)

I would always get the person some insulation from the ground and surrounding air. Ask the patient how they feel. Hot weather is the only time I would worry about possibly too much insulation. If they are sweating then it may be too much. Does this make sense?

Yes, typically with the sick and injured, shock is usually the cause of insufficient body heat. In an outdoor survival situation, I would want a radiant heat source like a flaming fire and a good reflective backdrop. The hypnotic effect of the flames seems to help distract people from their stress and helps them to calm down somewhat, which is a real help with pain stress. Keeping the shock victim comfortable and isolated from the elements also gives them a sense of security. If the victim gets hypothermic, consuming warming fluids goes a long ways to helping them get their core temps back up, assuming they are still cognizant enough to imbibe on their own. If not, then it is sharing body heat in a sleeping bag.

In general though, I'd be focusing on keeping the extremities well insulated, and stabilizing the victim in a sheltered area.

Are "space blankets" good enough to provide temporary insulation? They have become mandatory in Germany for first aid kits in cars, but I recently heard that they are not really that useful.

Space blankets reduce the loss due to radiation and convection. They can provide a confined space that can be kept warm more easily (insulation is provided by the trapped air in this case). The space blanket does not provide significant heat insulation (putting it under the body doesn´t help too much for this reason). Unless the space blanket is punctured it will keep moisture away. There is better gear but it may not be feasible to have it with all the time.
In the case of the car kit it´s a better than nothing approach. The space in that box is very limited after all.
In conclusion I´d say that the space blanket can help to reduce heat loss when used properly. In many cases they may be all you have so learn how make most of them.

It depends on what kind of "space blanket" you're talking about.

If it's the thin mylar ones that compress down to about the size of a pack of cigarettes, then yes, my personal opinion is that their value for insulating the victim from rain/wind/drafts is good, BUT, their value for warming a victim is practically nil because they depend on whatever warmth the victim can generate to bounce or reflect it back to him.

If you're talking about the more robust "sportsman's blanket," which has a stiffer backing (usually some kind of rip-stop material) and takes up a lot more space, then yes, these provide both a barrier and some true insulative qualities because of the nature of the material.

Either one is better than nothing, and the space blanket’s small size is what merits its inclusion in many PSKs, but it would be foolish to depend on that alone to save your life in a blizzard or other extreme situation.