|Top of the Hill||Boots and Blisters||Business as Usual:Meeting Minutes|
|Mini Lesson||Public Relations||Disclaimer/Copyright|
| Recent Missions
|| Callout Information
|Top of the Hill||by Aaron Hall , President|
President: Larry Mervine
Vice President: Tony Gaier
Secretary: Aidan Thompson
Treasurer: Lili Ziesmann
Membership: Bob Baker, Alex Fischer
Election of new officers will take place at the December meeting (which will also be our annual holiday party).
We received an invitation from REI this month to apply for a $3000 Conservation and Recreation Grant. The grant can be cash or gear. The other officers and I have put together an application for gear. The gear would be used to create five hypothermia rescue kits for our gear cache. The kits would consist of all the gear necessary to warm, clothe, and shelter a hypothermic subject. The intention of putting together kits like this is that we would be able to deploy them with our hasty teams on winter missions. Deploying these kits would reduce the chances that all of us would use our personal gear (sometimes our only extra clothing layers and food) to rescue a hypothermic subject. Kits like this would help the subjects and would increase our own safety on winter missions. More detail on this grant application will be given at the business meeting.
On the subject of hypothermia, winter is on its way and its time to go through your pack and throw in those extra clothing layers, hats, gloves, and stoves. Its also time to eat those caramel and nougat filled candy bars and replace them with candy bars that don't turn into rocks when they freeze. Mmm...Mmmmm.....
|Boots and Blisters||by Steven Buckley, Training Officer|
|Business as Usual:Meeting Minutes||by Joyce Rumschlag, Secretary|
Other items under old business included the land nav. eval. Aaron would like to draft a proposal so the team could vote on any changes to the evaluation by years end. The trainings would also have to be modified to accommodate training on skills that will be tested on in the eval. Tony Gaier agreed to work on the wording of the proposal for the next meeting.
Call out procedures were again addressed and it was decided that instead of the 5 minute wait it would be reduced to 2 minutes. The initial message on the hot line would only include basic essential information followed up by a more detailed message after the count of mission goers was obtained.
Purchase of pagers was again brought up with the team voting 12-1 to purchase 15 pagers that would be group page only. Members could acquire one of these pagers with a $22. deposit. Again the problem of "taking longer to tie in a subject than the haul would take" was discussed. Tony Gaier will bring in pictures to the next meeting of systems using webbing and buckles that are permanently attached to the litter.
Nominations for next year's officers took place yielding the following: President - Larry Mervine, Vice-President - Tony Gaier, Secretary - Aidan Thompson, Treasurer - Lili Ziesmann, Membership - Bob Baker and Alex Fischer.
Meeting was adjourned at 2110.
|Mini Lesson: Hypothermia||by Mike Dugger|
Even if we have plenty of food and water available, there are limits to how much heat our bodies can produce. Our ability to generate heat by physical processes is limited by our level of fitness. Fit people can supply oxygen to the bloodstream much more efficiently than unfit people, and oxygen is critical for our bodies to metabolize food. Availability of oxygen can also be affected by altitude. Oxygen depletion in the blood and tissues (hypoxia) will also limit heat production. Depletion of glycogen, a starchy substance converted easily to sugar by the body, can reduce the body's ability to generate heat through shivering and aerobic exercise.
Conduction is the flow of energy (or heat) from a warm surface to a cold surface by direct contact. Hold a metal rod at one end and put the other end in cold water, and the end you're holding eventually gets cold. This occurs by conduction of heat down the rod away from your hand. The same thing happens when you hold a glass of iced tea, or sit on a cold rock.
Convection occurs when heat is transferred by a moving fluid, such as air flowing over your skin or clothing. This is why there is such a thing as "wind chill." Water can also be the heat transfer medium, and heat can be carried away much faster by cold water flowing over the body than by air. The faster the fluid is moving, the faster the heat loss will be. The rate of heat loss also depends upon the surface area exposed to the fluid. In this case, the surface is the skin, and the surface area of our skin is about 2 square meters. Convective heat loss can be reduced by wearing wind-proof garments and a hat.
Radiation is the method by which the sun heats the earth. In this case, energy is transmitted as electromagnetic waves, without any direct contact of the surfaces or exposure to any heat transfer fluid. Thermal energy is radiated primarily at infrared wavelengths. You can experience radiative heat transfer by holding your hand facing a bright light bulb. Without contacting the bulb, and even if there is a slight breeze blowing from your hand to the light, you can feel the heat on your hand. This is also why the side of a house sitting in the sun all day feels warm, even if you don't touch it. Again, clothing can help minimize heat losses by radiation.
Energy can also be transferred by a phase change in a material. For example, it takes energy to boil water on the stove. As long as the water is boiling, the temperature of the water does not change. We are simply using energy to change the phase of the water from liquid to gas. On the body, this method of heat transfer manifests itself as evaporation. It takes energy to evaporate water, just like it takes energy to boil water on the stove. The energy to evaporate sweat comes from our bodies. The rate of energy loss by evaporative cooling depends on the wind (carries moist air away), humidity (how much additional moisture the air can hold), and temperature. About 2/3 of energy lost by evaporation is from the skin, and 1/3 from the lung during respiration. Energy loss through the lungs by evaporation during breathing obviously increases as the respiratory rate increases.
Infants and elderly people are most susceptible to hypothermia [1-3]. Infants have a larger body surface area to mass ratio than adults, allowing greater heat loss. Infants also cannot produce as much heat as adults through muscle activity. Metabolism decreases as we age, so elderly people have more difficulty maintaining body temperature through metabolism in cold climates.
As body temperature drops, brain function slows down. Higher functions like logic, reasoning, and the ability to solve problems are the first to go, and decline as the core temperature drops below 95 degrees F. Cerebral metabolism decreases by 3.5% for every 1 degree F drop in core temperature. This explains why hypothermic people may appear to be drunk or incoherent, not making sense. The EEG is flat (no brain activity) at 70 degrees F.
The heart rate initially increases as the core temperature drops, in an attempt to deliver more oxygenated blood to the tissues and fuel the increase in metabolism. Below 92 degrees F the heart rate decreases, and abnormal heart rhythms, or arrhythmia, may occur below 90 degrees F. Cardiac output decreases rapidly with decreasing core temperature, and is about 50% of normal at 77 degrees F. The body's ability to assimilate oxygen decreases due to reduced lung capacity by muscle constriction in the chest, resulting in decreased oxygen consumption.
In severe hypothermia, 86 to 82 degrees F, the subject will appear to be in a stupor, and may have fixed, dilated pupils and no reflexes. Respiratory arrest may follow.
Death occurs at a core temperature of about 70 degrees F, when brain activity stops. Be aware that even though a hypothermia victim may appear dead, full resuscitation and recovery is possible, although unusual . Always act on the premise that "no one is dead until warm and dead" . Now what about cold water drownings, you ask? Subjects exposed to very cold water cool off so fast that the brain's need for oxygen is dramatically reduced before damage occurs. With proper treatment, cold water drowning victims have been resuscitated after an hour in the water.
To fight hypothermia, continued heat loss must be prevented, and steps taken to increase heat production by the subject. Heat loss can be prevented by interrupting the heat flow away from the subject by the pathways discussed above. To stop conduction, insulate the subject from the ground or other cold surfaces. Stop convective heat loss by providing shielding from the wind. Prevent radiative heat loss by making sure that all exposed areas of the body are covered with insulation. Finally, stop heat loss by evaporation by making sure the subject is dressed in dry clothing.
In mild hypothermia, the subject's own heat production rate can be boosted by increased physical activity and oxygen use. Provide the subject with water and food, to increase metabolism. Hot chocolate or other warm, sweetened liquids (no caffeine) can be offered to a conscious subject. At high altitude, administering oxygen can help the subject's body generate heat. If field evacuation is not imminent, external heat should also be provided. This may be as simple as building a fire or getting the subject into a heated (and properly ventilated) tent. Chemical heat packs or hot water bottles may be applied to armpits, groin, and neck to heat the body, but be careful. These can get hot enough to cause burns. Direct body to body contact with the subject is a very effective method of warming. Make sure to replace fluids in order to prevent dehydration.
Rewarming must be done carefully for subjects having moderate-to-severe hypothermia which developed over a prolonged period of time. For example, rewarming by application of external heat may be hazardous because it is likely to cause sudden dilation of blood vessels close to the skin (vascodilation), allowing cold, lactic acid-rich blood to return to the core. This cold blood flowing into the core will reduce the core temperature even further (convective afterdrop), and change the blood pH [5-7]. Cold blood returning to the heart may be enough to put the patient into ventricular fibrillation. To prevent vasodilation, it is important that the patient's core be rewarmed before the extremities. For the same reason, even a conscious patient having moderate hypothermia must be handled very gently and not be allowed to exercise, as muscular action can pump cold blood to the heart.
Equipment for proper core rewarming of a severely hypothermic subject may not be readily available in the field. In this case, the best course of action may be to insulate the subject to prevent further heat loss, and transport them as quickly as possible to facilities with proper equipment.
If CPR is necessary, it is important to be aware that it may be more difficult on a hypothermic subject. Decreased core temperature and muscle constriction may make the heart and thorax stiff. Blood flow may be poor due to vascoconstriction, and will exhibit increased resistance to flow through the body. A cold heart muscle may not return to a normal rhythm as easily as one at normal temperature. There will also probably be additional challenges to effective CPR technique, such as the need to transport, and environmental factors such as wind and snow. Also be aware that the pulse may be very slow and difficult to detect in a subject suffering from severe hypothermia.
|Public Relations||by David Dixon|
I am working on redoing our pamphlet I had previously redone a few years ago. We need to include something now on medical and some better, updated photos. I will have some current pamphlets available at the business meeting for anyone interested in giving their two cents worth. Email me your valuable comments.
We have no upcoming P.R. events and since the last Wednesday of November is the day before Thanksgiving and the last Wednesday of December is New Year's Eve there will be no committee meeting until January.
|Disclaimer and Copyright notice||the Editors|