Wilderness First Aid Basics

When an emergency strikes out in the wilderness, your quick response could mean the difference between life and death. Addresses breathing problems, cold problems, shock and dehydration.

wilderness first aid

Anytime you are exerting yourself physically, drink enough water to maintain proper hydration.


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Breathing Problems

Many an injured person has died needlessly in the wilderness simply because he was left lying on his back while someone went for help. In most cases, he became unconscious and his relaxed tongue fell back and blocked his air passage. III some cases he vomited, and because he was on his back and unable to help himself, he got some of the vomit into his lungs. The acid in the vomit caused a fast-acting pneumonia, which killed him quickly. In still other cases, blood from his nose or mouth collected in the airway and he asphyxiated.

If his companion had simply placed him on his side and braced him there before going for help, he might not have died. What a simple thing to make the difference between life and death! An Unconscious person who is placed on his side to protect against fluids in his airway is said to be in the recovery position, because in that position he may regain consciousness without danger of suffocation. It is also called the drainage position because it allows fluids to drain from the mouth and throat without blocking the airway. Placing ail unconscious casualty in this position is one of the most basic parts of first aid.

Other casualties have died because they could not get enough air. Again, simple body position makes a difference. A person lying down cannot breathe as well as one sitting up. This is because when we lie down, our intestines tend to move up and push against the diaphragm, the flat sheet-like muscle that separates Our lungs and vital organs, and helps us to breathe. Lying down keeps the diaphragm from working well, so we get less air into the lungs. That is why people with breathing problems such as chronic obstructive pulmonary disease (COPD), emphysema, or asthma prefer to sit up. 'that is why we put people in a sitting or semi-sitting position whenever they have trouble getting air.


Our body needs warmth almost as much as oxygen. Actually, it is the burning of oxygen in our body that produces warmth, so these issues are related. If the inside temperature of our body drops only a few degrees, our brain and other organs do not work as well. If our interior (core) temperature drops to the air temperature of a warm summer day, we may die.

Anyone who is sick or injured is much more vulnerable to cold than is a healthy person. He feels the cold more and is less able to produce heat to fight it. Less blood flows to his skin to keep it warm. Because of this, he may get frostbite or suffer from exposure more easily.

In warmer climates, maintaining body warmth is considered an important part of first aid. Imagine how much more important it is in the northern wilderness! Even in summer, the north is rarely a truly warm place. In any other season it is often bitterly cold. So, protecting a casualty from further cold exposure is of primary importance, once it has been established that nothing immediately threatens the casualty's life. Usually, it is simply a matter of covering the casualty with an adequate sleeping bag or blankets or extra clothing-but don't forget to put something underneath too. A major part of body heat is lost to the ground, and moisture easily seeps in from dirt or snow.

Later on, even after first aid is completed, the casualty will still be very sensitive to cold. It is quite possible for him to get frostbite inside a heavy sleeping bag if he is being transported on an open sled or similar vehicle. Always be extremely careful to keep the casualty warm and dry, and watch for the signs of hypothermia (exposure) any time conditions are marginal.

A true story shows the importance of this. Five men on a ski trip in the mountains encountered bad weather. One of them was sick with gastroenteritis (stomach flu), so they decided to make camp. That night it snowed heavily. In the morning, the sick man was still ill and the snow was too deep for him to travel. The other four decided to go back to town for help. They left the sick man wrapped in two down sleeping bags, in a good tent, with a stove and food close by. Two days later a rescue party reached his tent. He had been dead for about a day, from hypothermia. There was nothing else wrong with him but gastroenteritis. In his weakened condition, his body wasn't able to produce enough heat to balance the heat loss, even in two sleeping bags. Keep on the lookout for hypothermia in all northern-climate casualties, and be ready for it.


Shock may be present with almost any injury or illness, and is usually present in any serious one. Shock is what occurs when there is inadequate organ perfusion; that is, decreased oxygen passes through the organs. To understand this, we need to know how the circulatory system works.

The heart is a pump. The veins and arteries work like flexible hoses, carrying blood to and from every part of the body. Near the heart, the arteries carrying blood from the heart are large. They branch often, and get smaller and smaller. Finally, at the outer ends of the branches, they become so fine that parts of the blood pass through their walls. This blood reaches each cell of the body, bringing oxygen and food to it. The food and oxygen are used or "burned" in the cells, keeping the cells healthy and producing the heat needed to live.

When the blood leaves the cells, it carries their waste products back into tiny veins, which pour into larger ones and finally into the largest veins which feed directly into the heart.

Now the blood has almost made a round trip-but there is one more stop before circulating once again. The heart pumps the blood to the lungs and back to the heart. In the lungs, the blood loses the waste gases (mostly carbon dioxide) it has picked up in the cells, and each red blood cell picks up a new load of oxygen. Then it returns to the heart and the heart pumps it again through the arteries to the cells.

The most important point of this whole process is the provision of oxygen and food to the cells. If this is interrupted for only a few minutes, cells start to die. If the cells that die are in the vital organs especially the brain, heart, or kidneys-the whole body will also quickly die. When organs are not getting enough oxygen to work properly, the signs of shock start to show. But what causes shock? In order for the blood to get oxygen to the cells, the blood has to be under some pressure. This pressure is provided by the pump-the heart-and maintained by the veins and arteries, which are able to get slightly larger or smaller to control the pressure.

Several things might cause this pressure to drop. If there is a "leak" in the system, from a bad cut, blood flows out and the pressure drops. The body tries to deal with this automatically.

Bodily Responses

  • Skin becomes pale and cool
  • Pulse increases
  • Breathing rate speeds up
  • Thirst
  • Nausea
  • Confusion
  • Shortness of Breath

Several types of illnesses can bring on shock by causing the large blood vessels in the trunk to loosen and expand. The vessels become bigger and can hold more, but the amount of blood in them remains the same, so the blood pressure drops. Sometimes a severe emotional shock can cause this to happen. (Fainting is not the same as shock, but it is caused by a shortage of blood to the brain.)

A violent allergic reaction to a drug or insect sting can cause shock. So can injury to the spinal cord.

Once shock starts, it may be difficult to reverse. If it is not stopped or reversed, the casualty will die.

Preventing Shock

  • Ensure a good airway
  • Control bleeding
  • Lie the casualty down with feet raised eight to 12 inches
  • Keep the casualty warm
  • Avoid rough handling
  • Reduce pain as much as possible
  • Reassure the casualty

Since the problem is basically one of oxygen shortage to the cells, you must be sure that the casualty is breathing with maximum efficiency. Since low blood pressure is a factor, you must be sure no more blood is lost. Raising the legs increases return of blood to the heart. Keeping the casualty warm is especially critical because the skin, with a decreased blood supply, is more vulnerable to injury from cold. Rough handling increases shock. So does pain. And reassurance has been shown to have a positive effect on blood pressure and certainly on the casualty's survival attitude. The first-aider should not be fooled into thinking there is no shock problem if shock does not appear immediately after blood loss. The body compensates in so many ways for the initial blood loss that pressure may be maintained for a time. With continuing loss, shock may appear rapidly.

Dehydration Causes

  • Not drinking enough
  • Excessive perspiring
  • Evaporation from breathing
  • Vomiting, diarrhea, frequent urination

Because of the cold, very dry air of the north, especially in winter, evaporation is very rapid, and a person who is working hard outdoors for several days with little opportunity to drink may become severely dehydrated, and may show signs and symptoms similar to shock. But dehydration by itself is not usually the main problem, for almost everyone, if they can, will eventually satisfy his thirst with the needed fluids. The combination of dehydration and other conditions, though, may be a real problem.

Suppose, for example, an active hunter has lost 5 percent of his total blood volume by dehydration. The body will compensate-much as it does in shock-by reducing blood flow to the skin. This makes the skin colder and more likely to be frostbitten. Suppose the hunter is injured and loses blood. Since his blood volume is already decreased, it takes less blood loss to produce shock. Suppose that same hunter had a chest injury or a respiratory infection. Because the body fluids have become more viscous (thicker and stickier) from dehydration, it is harder for the hunter to cough up the fluids which accumulate in the lungs.

To balance normal water loss, simply drink more water during outdoor activity. Try to drink often even if you don't feel thirsty. The traditional tea stop while traveling is very valuable in this and other ways, although tea and coffee are not as good as plain water, because tea and coffee are diuretics (they make you urinate more). Alcohol should not be drunk, as it increases dehydration (much of the discomfort of a hangover is due to dehydration).

Although you can reduce thirst for a short time by nibbling on snow, remember that melting any amount of snow in your mouth takes an enormous amount of heat from your body and produces little water. Any water you can get, no matter how icy, will use up less body heat and be more thirst-quenching. Most northerners have heard stories about people who were trapped without water and "survived" by drinking their own urine. If the stories are true, it is likely that they survived in spite of drinking urine, not because of it. Neither urine nor sea water should be drunk, even in small quantities, as the salts in them will draw further water from your tissues.

Dehydration by normal means is best combated by plain water or other ordinary drinks. Dehydration due to vomiting or diarrhea should be fought using Gatorade or a salt, soda, and sugar mix.

A mildly dehydrated person may show some or all of the following signs.

Mild Dehydration

  • Thirst
  • Dry tongue
  • Discomfort
  • Tiredness
  • Nausea
  • Sleepiness
  • Pale, cool, clammy skin
  • Fast pulse
  • Little or dark urine
  • Crying without tears

A healthy person getting adequate fluids will produce at least 1,000 ml (about four cups) of urine every 24 hours. Observing an output of significantly less in a casualty, even if the above signs are not manifesting themselves, is reason enough to be concerned.

Adapted from The Wilderness First Aid Guide (McClelland & Stewart, Inc., 1994) by Wayne Merry. Copyright © by Wayne Merry.