Jan 5, 2017

Hypothermia – The Silent Enemy

By: Adam Walton

It’s 3:00 pm on a frigid day and you just shot a nice buck. A half hour later you get down from your tree stand and find a blood trail left by your trophy. As you track after him, you come across a shallow narrow creek, which the buck apparently crossed. After checking the depth, you determine the 1 foot of water can easily be crossed. However, as you step in, you trip on a rock and fall belly first into the water. You quickly get back to your feet and brush off the inconvenience before continuing on with tracking your buck. The blood trail leads you deeper into the woods and before long dusk moves in.

A short time later, you find your dead buck and proceed to field dress the animal. By this time darkness has set in, but your familiarity of the area leaves you feeling confident there will be no problems getting home. As you lug the buck through the woods, you begin to sweat from the hard work of dragging the carcass. The weight of the deer is heavier than expected and dragging it out is taking much longer than anticipated. You soon begin to get cold and start shivering mildly. You continue forward, shivering more and more, to the point it becomes uncontrollable. Shortly after, you start to become confused and can’t remember the exact way out of the woods. You move on, but your confusion now has you going the wrong direction and you soon become disoriented. At this point, your shivering has stopped and you become so confused you leave the buck carcass. As you stagger through the woods aimlessly, your body becomes more and more tired, while your mental state deteriorates even more. Well into the evening now, all your rational thought is nonexistent as you stop to sit near a downed tree. After sitting a short time, weakness and tiredness completely take over…You easily slip into a deep sleep. Later that night, worried family members form a search party and they head out to your last known location.

It’s 3:00 pm and you haven’t seen a thing pass your tree stand all day. A strong cold front has begun to move in, so you decide to head in early. As you begin your decent down the tree, you slip and fall 15 feet to the frozen ground. Immediate pain shoots through your right leg and you quickly realize it is badly broken. As you lay on the frozen ground, you remember your cell phone is sitting inside on the console of your truck. After helplessly laying on the ground for over an hour, coldness sets in and you begin to shiver. Thankfully, you have a few survival items in your coat pocket, including a small knife, matches, and a whistle. Although the pain is immense, you’re able to move enough to gather some small nearby tree branches. It takes a few attempts, but you light a small fire with the matches and are able to keep it burning with old foliage around you. Later that night, worried family members form a search party and they head out to your last known location.

The scenarios above both have very different outcomes. Before we conclude those stories, let’s first take an in-depth look at hypothermia.

Hypothermia is defined as: “The condition of having an abnormally low body temperature, typically one that is dangerously low.”

Hypothermia occurs when heat escapes from your body faster than it can warm itself. Body temperature that is too low affects the brain, causing confusion, poor decision making, and the inability to move well. This makes hypothermia very dangerous since a person may not know it is occurring to them. Most people tend to associate cold outdoor weather with hypothermia; however it can occur in any situation where temperatures are below normal human body temperature. Victims of hypothermia often are elderly people, in fact from the 700 annual deaths; half of the victims are over 65 years old. People who remain outdoors for long periods such as ice anglers, hikers, hunters, etc. and people who drink alcohol are also prone to hypothermia.

Depending on the speed of body heat loss, hypothermia can occur rapidly or develop very slowly. Rapid onset can occur within minutes, while delayed onset can build up over days. Five ways the body can lose heat take place through Convection, Conduction, Radiation, Respiration, and Evaporation. Convection is commonly caused from strong cool winds, while conduction occurs from direct contact, such as lying on frozen ground or being submerged in cold water. Radiation, respiration, and evaporation of body heat occur naturally. Radiation of body heat can be controlled by wearing proper clothing, while respirations and evaporation (sweating) can be controlled by minimizing over exertion.

Recognizing the signs and symptoms of hypothermia are important not only to you, but also to those around you since onset often goes unnoticed until it’s too late. Depending on the severity, symptoms of hypothermia may include shivering, confusion, uncoordinated movements, tiredness, memory loss, and poor speech.

The three stages of hypothermia are discussed below. Their temperature ranges can vary some depending on your reference, but generally they are in agreement of a few degrees. This data came from a recent cold weather presentation Dr. Ken Hanson* gave to healthcare providers. Also, please remember a victim can go through each stage very rapidly if conditions allow.

  • Mild hypothermia - Body temperature ranges between 90 F to 95 F and the victim typically shivers to maintain body temperature.
  • Moderate hypothermia - Body temperature ranges between 86 F to 90 F and shivering gives way to slight confusion, uncoordinated behavior, and tiredness. Metabolism and body functions slow considerably.
  • Severe hypothermia - Body temperature is below 86 F and all shivering stops. Mild confusion leads to complete disorientation, irrational thought process, and then into lethargy. The victim will slip into a coma and die if help does not arrive.

Treatment for hypothermia depends on the severity or stage the victim is in. In cases of mild to moderate hypothermia, remove any wet clothing and get the victim to a warm area. Gradually rewarm them by applying a mild source of heat to the groin, head, neck and sides of the chest. Do not rapidly rewarm any victim of hypothermia. Warm beverages can also help increase the body temperature, but do not give alcoholic beverages. Alcohol actually lowers the body’s temperature.

Treatment for severe hypothermia is true medical emergency and will need to be handled by trained medical professionals. If you come across this situation, first call 911. People who have severe hypothermia must be carefully re‐warmed and their temperatures monitored. If applicable, remove all wet clothing and wrap the person warmly. Do not rub the person and try to keep movement of them to a minimum. Do not use direct heat or hot water to warm the person. Warming a victim of severe hypothermia too fast will cause cardiac arrest. If the victim is unconscious, check for a pulse. This should take no longer than 10 seconds and if there is no pulse detected or if you’re unsure, begin CPR efforts. CPR should be continued while the victim is being warmed, until the victim responds, or medical aid becomes available.

The hunter who tracked his trophy buck at the beginning of this article did numerous things wrong. Hypothermia was able to quickly set in after he got wet from tripping in the small creek and over exerted himself while dragging the deer. Since the victim didn’t even realize a major problem was developing, hypothermia was able to take hold without him knowing. Unfortunately, a search party found his lifeless body the next morning…propped up against the tree he sat down by.

Although moderately hypothermic, the hunter who fell from the tree stand and broke his leg was found alive thanks to a little preplanning. Carrying a small survival kit or a few important items shouldn’t be overlooked. A simple kit may include a waterproof fire starting device, Swiss Army knife, 6’ parachute cord, and signaling device. These items take up little space and can easily be carried in a large coat pocket.

Please plan accordingly for your next outdoor adventure and remember hypothermia can sneak up on its victims. The slightest sign or symptom shouldn’t be ignored…especially if you’re alone. Don’t become a victim and stay safe!

For more information on cold water exposure, check out our video demonstration. See how cold affects the body in real time and learn a few ways of getting out of the water if you were to fall through thin ice. Video link: https://www.youtube.com/watch?v=QKpAzvXSldA

Author    

Adam Walton is the owner of Pike Pole Fishing Guide Service, located in Southern Wisconsin. He is a multi-species charter Captain and also a Wisconsin certified Firefighter/Paramedic. Along with many years of fishing, Adam has 20 years of experience in the Fire/EMS field. For more information, check out www.pikepolefishing.com.  

Reference Assistance *

Dr. Ken Hanson is an Emergency Medicine Physician who is also subspecialty boarded in EMS. He currently works for the Mercy Health Systems MD-1 program in Walworth County Wisconsin. https://ems.mercyhealthsystem.org/team/ Dr. Hanson also has 20+ year of military experience as both a Diving Medical Officer for the US Navy and as a Flight Surgeon for the Air National Guard. He also has an interest in Wilderness Medicine.