98.6 Degrees: The Art of Keeping Your Ass Alive Read online

  Chillin’ Out: A World Record

  The dubious honor for the world’s lowest recorded body temperature in an adult, with ultimate survival, goes to an anonymous 23-year-old homeless woman found sleeping on the streets of Chicago. The outside air temperature at the time was -11°F (-24°C). Although she was thought to be dead upon arrival at the hospital, doctors discovered that her heart was still slowly beating. Her core temperature was an unbelievable 64°F (18°C)!

  In time, your metabolism speeds up, burning extra calories in order to produce more heat. But the body has only so many tricks up its sleeve without outside help. Regardless of how many candy bars you can cram into your mouth, when outside temperatures drop and you’re stuck with limited clothing, you won’t be able to sufficiently increase your metabolic rate to replace the heat you’ll lose to the environment.

  A Cold-Blooded Killer

  Humans are amazingly poor in their ability to physiologically adapt to cold environments. The brutal effects of cold weather and the toll they take on human life are legendary and are responsible for decimating countless armies throughout history. Alexander the Great was knocked off by hypothermia, as well as countless Roman legionnaires in the high country. In his attack on Russia, Napoleon’s once proud, 500,000-man army, through the combined insults of combat and cold, were reduced to about 40,000 men. Many who survived did so by killing their horses and crawling inside the warm carcasses while others, desperately hungry from the cold, pillaged local medical schools to eat preserved human organs. In World War I, cold-weather deaths for combined British, French, and Italian forces were estimated as high as 233,000 individuals. Even in the face of such amazing statistics, bear in mind that the majority of deaths from hypothermia happen when air temperatures are between 30°F (-1°C) and 50°F (10°C).

  When It’s Hot

  There are approximately 400 environmental heat-related deaths every year in the United States, with thousands more occurring during heat waves, droughts, and increased illegal immigration in the Southwest. When it’s hot outside, heat must be lost to maintain body temperature. Increased surface blood flow through dilated vessels, especially in the arms and legs, works at dissipating extra heat by exploiting the major surface areas of the body as well as avoiding the insulating properties of subcutaneous fat. Again, if you allow your blood to turn to ketchup through dehydration, this activity is severely compromised. This, coupled with the wonders of evaporative heat loss through increased sweating, is the main tool your body uses to stabilize its inner core when environmental temperatures climb.

  Charts and graphs in books bore me silly. That said, if I didn’t include a signs-and-symptoms chart for hypothermia and hyperthermia I’d be a doo-doo head. A sign is a condition(s) you see in someone else while a symptom is a condition(s) you tell someone else. While looking at the illustration on the opposite page, note that the psychological signs and symptoms of hypothermia and hyperthermia are very similar, involving disorientation and poor coordination. These similarities are no accident and offer vital clues into a person’s physiology. Being able to recognize the signs and symptoms of exposure in yourself and others is mandatory, as these are the body’s warning signs that things are getting out of whack on a cellular level. The majority of people who die from exposure have ample early warnings that they flat out ignored. These signs are your second chance to circle the wagons and manipulate your environment in whatever way you can to prevent heat loss or gain and the sooner the better. Ignore the signs, especially those occurring from the onset, and you might feed worms. Keep in mind that the signs and symptoms shown include only behaviors that can be readily understood in the field using no medical gear.

  Signs and Symptoms of Hyperthermia

  There are three levels of environmental heat illness recognized throughout the medical profession. Listed in the order of their severity—from “hey, let’s rest in the shade and cool down a bit” to “why is Uncle Frank curling up in the fetal position while in a coma?”—they are heat cramps, heat exhaustion, and heat stroke. There are two types of heat stroke, classical heat stroke and exertional heat stroke. Classical heat stroke generally occurs in sedentary older folks who decide to mow the lawn at noon in July. Exertional heat stroke happens after intense physical activity in a hot environment, especially during periods of high humidity, which prevents the cooling power of evaporation. During this type of heat stroke, despite earlier beliefs, the victim may still be sweating heavily as the sweat glands are usually still active at the time of collapse. As suggested, heat stroke is one bad dude and should be avoided at all costs by paying attention to the signs and symptoms of heat cramps.

  How to Screw Up a Cell Membrane

  Biochemicals are molecules constructed by a living system. Living systems are composed of large units, such as organs, muscles, and bones, and small units, such as cells that form the large ones. The human body is composed of around 50 billion cells, all of which contain water, among other goodies, and change viscosity, pH, and electrostatic charge. Even smaller units called organelles lie within the cells themselves and come neatly packaged. Cell membranes or “walls” are permeable and consist of lipids or fats—saturated fats to be exact—and are stacked like shelves holding all sorts of life-giving matter. Through these wall-like membranes, cells make and break bonds at precise rates, such as our sodium and potassium balance. The membranes, being made of fat, are very sensitive to changes in temperature.

  When the body’s temperature drops, proteins within the cells start to clump, creating holes, while water in and around the cells freeze to form jagged ice crystals that shred the delicate membranes. When the thermometer rises, cell membranes begin to lose their elasticity and can actually melt. With cell membranes frazzled, precision rates are altered and once-pristine body systems fall into a state of unregulated pandemonium. Fluctuations in core body temperature literally cause chaos on a cellular level, chaos you can see in the uncoordinated signs and symptoms of hypothermia and hyperthermia.

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  HOW YOUR BODY LOSES AND GAINS HEAT: THE PHYSICS OF FREEZING YOUR FANNY OR BAKING YOUR BONES

  Here on Earth, your body loses and gains heat through several physical laws described below. Unless you’ve progressed enough spiritually to tap into higher realms, all life, to a greater or lesser extent, is bound by these laws. By recognizing the general physics involved in heat loss and gain, the survivor can intelligently assess virtually any situation placed before them and deal with the problems one by one. Don’t freak out on the big words; just understand the simple principles behind them. Life, after all, is very simple—we choose to make it complex because it’s better for the economy.

  Conduction

  Conduction is the transfer of heat through direct contact with an object, including hot or cold air against the skin. The direction of heat flow is always from a warmer to a cooler temperature. Anytime you touch something that’s less than 92°F (33°C) (your approximate normal skin temperature), you lose heat through conduction. If the object touched is warmer than 92°F (33°C), your body gains heat. Substances vary in their thermal conductivity quite radically. Water has twenty-five times the conductivity of air, while muscles possess nearly twice the tissue conductivity of fat. Unless you find yourself frequently floating, feet or other parts of the anatomy are in constant contact with the ground, hence the need for insulation in hot and cold environments. Hot desert ground temperatures can become almost unbearable. One summer, while “reconning” for a desert survival course, I completely delaminated the soles from a new pair of sandals in less than thirty minutes! Under normal conditions, conduction accounts for approximately 2 percent of the body’s heat loss for a standing person.

  Convection

  Convection is the transfer of heat through currents in air and liquids and can be either forced or natural. An example of forced convection would be rolling down the windows of a moving car or sitting in front of a fan. Natural convection happens when density changes in heating o
r cooling molecules next to the body cause them to move away from the body itself. We all possess a boundary layer of slower moving molecules directly against our skin that is produced by the body’s radiant heat. This layer, which is only a few millimeters thick, equals a constant three-mile-per-hour wind. For example, anyone who climbs into a scalding hot tub will do so very slowly and with much grimacing. After sitting still for a few minutes, however, the heat doesn’t seem to be nearly as potent ... until some dimwit bumps you and disturbs your boundary layer. All of a sudden, the water miraculously seems a lot hotter.

  Classic convection experienced by every outdoor traveler is the wind. “Wind chill,” a term coined by American explorer Paul Siple, causes existing outside air temperatures to feel a heck of a lot colder than they actually are and is a common killer of all outdoor enthusiasts, as it greatly increases the possibility of death through hypothermia. In contrast, hot desert winds can feel like a hair dryer on the skin. They suck away evaporating sweat so quickly that you might not think it’s hot because it appears as if you’re not sweating. Sweat evaporating from the skin at such an accelerated rate does little to help cool the body. According to paleoanthropologists, the oldest structure ever found is a windbreak built by early hominids in Africa more than 3.25 million years ago, proving that protection from the wind has been in vogue for a very long time.

  Convection features almost as many variables as there are corporate tax breaks, including surface shape, density, surface temperature profiles, flow dynamics, conductivity, and specific heat. This crazy variation means that convective heat loss or gain is a wilderness wild card that can cause you to push up daisies. Researchers have found that under neutral conditions, 40 percent of the heat loss from a naked human body stems from convection—add wet clothing and/or strong winds to the scenario, which are common occurrences in the outdoors, and the percentage climbs drastically.

  Radiation

  Radiation is the act of losing or gaining heat through radiation. There are two types of radiation we’re concerned with. Terrestrial, or long-wave radiation, emanates from fire, a human body, or just about anything else on the planet having a temperature greater than absolute zero or -460°F (-273°C). Radiated body heat is the emission of electromagnetic energy in infrared wavelengths of which the body is both emitting and receiving. Curling up in the fetal position reduces your radiant heat loss by 35 percent, compared to a person standing with arms away from their sides. Snuggling next to your honey on a cold winter night means you’re enjoying his or her long-wave radiation, which for mammals is somewhat constant. Creativity with this concept can result in a grab bag of fresh pick-up lines at the neighborhood bar. Radiant heat loss is a force to be reckoned with, as it accounts for around 45 percent of the total heat loss from a nude body in neutral conditions. Surfaces that are good at absorbing radiation are also good at emitting it.

  Short-wave radiation emanates from the sun and varies in its intensity according to the time of day, altitude, latitude, surface reflection, atmospheric pollution, ozone levels, and season. Most ultraviolet radiation bathes the Earth at mid-day, 80 percent between the hours of 9 A.M. and 3 P.M. and 65 percent between 10 A.M. and 2 P.M. Radiation from sunlight can heat a person in three ways: directly on the skin, reflected off particulate matter in the atmosphere, and reflected off the ground. Unlike long-wave radiation, short-wave radiation is absorbed to a greater extent by darker colored clothing and skin pigmentation. In hot climates, all can lead to dehydration and hyperthermia if not properly managed.

  Evaporation

  Evaporation is the act of losing heat through the conversion of a liquid to a gas. The principal way your body loses heat in a hot environment is the evaporation of water in the form of sweat upon your skin, as well as a small amount of evaporative cooling gained from exhaled moisture. A gram of sweat evaporating off skin with a normal temperature loses about 580 calories/gm of heat. In the desert during July, the 2.6 million sweat glands humans have act as a savior. On the other hand, in the winter cold, clothing that is sweaty from over-exertion will place you one step closer to death by increasing your chance of hypothermia. Interestingly enough, most mammals don’t have sweat glands but keep cool by panting (evaporation through the respiratory tract), increased salivation, and skin and fur licking.

  How Your Body Gains Heat

  How Your Body Loses Heat

  Respiration

  Respiration is the act of losing heat and water vapor through the respiratory surfaces of the lungs by breathing. The air you inhale must be humidified by the body to saturation in order to be used efficiently. When this vapor is exhaled, the resulting evaporative heat loss at high altitudes can rival sweat as a cooling factor. More typically, however, respiration heat loss is minor in comparison to the others previously mentioned. A tremendous amount of water can be lost through the breath, especially in extremely cold temperatures. Cold, dry air breathed into warm, moist lungs pulls out as much as two quarts of water daily in -40°F (-40°C) temperatures. In some instances, the same condition can destroy the cells lining the respiratory tract.

  Cold Temperatures

  In summary, walking around in cold temperatures without insulated footwear or lying on noninsulated ground (conduction) while wearing sweaty cotton clothing (evaporation) in the wind (convection) without the ability to make a fire (radiation) can kill you.

  Hot Temperatures

  In hot temperatures, radiation from the sun (times three) directly on the skin, reflected off the ground, and reflected off particulate matter in the air, can heat up conductive ground surfaces in excess of 150°F (66°C). This helps produce heated convective winds capable of evaporating sweat obscenely fast with little cooling effect for the body. Add the crushing effect of metabolic heat produced by trying to dig the car out of a wash at noon, and you have a serious set-up for dehydration, hyperthermia, and death.

  The Cold-Weather Bottom Line

  1. Produce heat.

  Exercise using the body’s larger muscle groups (squats); eat calorie-dense foods, especially carbohydrates, frequently throughout the day; create fire in conjunction with space blankets or other reflectors if possible; locate south-facing microclimates for maximal sun exposure; hydrate using warm/hot fluids with dissolved hard candy or other sugars when available.

  2. Decrease heat loss.

  Wear proper clothing especially in the head, neck, and torso areas; replace wet clothing with dry; create or find shelter from the elements; decrease surface area while increasing volume; avoid or insulate the body from cold surfaces.

  3. Avoid becoming exhausted (60 percent rule).

  Working at 60 percent allows the body to burn fat reserves instead of using up glucose and glycogen stores. Get adequate sleep and rest.

  4. Reduce internal and external constriction.

  Avoid ingesting vasoconstricting substances; tight clothing, equipment, and footwear.

  5. Stay hydrated.

  Drink warm to hot liquids if possible; urine should appear “clear.”

  6. Stay aware of what’s happening.

  Be conservative. Don’t take unnecessary chances. Cultivate and maintain a “Party On” attitude.

  Once you are familiar with how your body loses and gains heat, it’s easy to understand how an innocent little day hike, through the compounded result of basic physics, can turn into a life-threatening state of affairs. In the case of lost or forgotten gear, learning the basics of heat transfer allows you to improvise insulation and other needs directly from the wilderness.

  The Hot-Weather Bottom Line

  1. Reduce heat gain.

  Stay in the shade; create or find shelter with air movement; insulate the body and avoid hot surfaces by going above or below scorching ground temperatures if possible; seek cooler north-facing microclimates with minimal sun exposure; avoid physical exertion during the afternoon; wear proper clothing; keep hydrated; save movement for early morning, late evening, or night.

  2. Increase heat
loss.

  Increase surface area while decreasing volume; wet clothing if possible, especially the head, neck, trunk, and groin areas; increase air movement; lie on or against cooler microclimates.

  3. Avoid becoming exhausted (60 percent rule).

  Working at 60 percent allows the body to burn fat reserves instead of using up glucose and glycogen stores; rest and conserve during afternoon heat. Get adequate sleep.

  4. Reduce internal and external constriction.

  Avoid ingesting vasoconstricting substances; tight clothing, equipment, and footwear.