Wherever you go at whatever time of year, there are environmental hazards. Beachgoers must avoid sunburn. Suburban gardeners keep an eye out for poison ivy and ticks. Every place has its dangers, but when they’re known and precautions are taken, they can be avoided.
The outdoors in winter has its own perils for the unprepared. Compounding the problem, these situations can be brought on or aggravated by the existence of the more common stresses facing a wilderness traveler: fatigue, dehydration, and the usual assorted knocks, scrapes, and bruises. The winter camper must exhibit an especially high level of awareness and vigilance when it comes to dealing with environmental hazards.
The most important and common winter camping hazards are hypothermia (the condition of having a lower-than-normal body temperature) and frostbite (the freezing of body tissues). These are medical emergencies occurring when the body is stressed to an excessive degree by the effects of cold weather. Another fairly common winter injury is snowblindness (the condition of having sunburned the eyes). Snowblindness happens when the eyes absorb high levels of ultraviolet radiation.
All of these conditions are preventable, yet every winter camper should be familiar with the symptoms and treatment of these cold- weather injuries.
Hypothermia
Hypothermia occurs when the body loses heat faster than it can be generated. If the loss isn’t arrested and the situation brought under control, hypothermia can be fatal.
Body heat is produced through eating, drinking warm fluids, and exercise such as walking, running, or even shivering. It can also be acquired from an external source such as the sun, a fire, or another warm body. Body heat is best maintained by carefully monitoring and controlling it like a precious currency; don’t spend it all in one place at one time.
Not all body heat loss is bad. Remember the layering principle: Layering allows excess heat to escape so you avoid a perspiration drenching. Uncontrolled heat loss is the enemy to be guarded against. The body loses heat in any of four ways.
- Radiation. A significant amount of body heat can be lost when it’s emitted directly into the environment because of a lack of insulation. An uncovered head, for example, radiates an enormous amount of heat that’s immediately dissipated and lost.
- Conduction. Heat can be lost through conduction when you come into direct physical contact with something cold, whether it’s the cold ground, frigid water, or clothing saturated with sweat, rain, or melted snow.
- Convection. Your body generates enough heat to keep warm the layer of air directly next to the skin. Your clothing maintains this warm layer by trapping it in the dead air spaces of the fabric. That layer of warm air can quickly be stolen by the wind–through convection–if you don’t wear proper shell garments.
- Evaporation. When you breathe, you inhale cold air, which is warmed to body temperature, saturated with moisture, and then exhaled. This continual replacement of warm, moist air by cold, dry air causes evaporative heat loss. Perspiration also contributes to heat loss because the body must generate considerable heat in order to turn the moisture to vapor and disperse it through evaporation.
Uncontrolled heat loss through any of these mechanisms or a combination of them can lead to a situation in which the amount of heat lost is greater than the amount your body produces. The result: hypothermia. Cold, wet, windy days are the times to be especially wary.
Stages of Hypothermia

Humans are truly equatorial animals. We need to maintain a constant body temperature of 98.6 degrees or we become quite uncomfortable. Even a drop of a few degrees impairs our ability to function normally or even survive–and a few degrees’ drop results in the early stages of hypothermia. A few more degrees results in deeper hypothermia. Here’s what to look for in cases of hypothermia.
- Early stages. The early stages of hypothermia (body temperature of 98.6 to about 95.0) are characterized by fits of intense shivering and an inability to control muscular coordination. The victim feels cold, tired, and confused.
- Middle stages. As hypothermia progresses (body temperature of 95.0 to 90.0) the victim continues to shiver violently–the body’s way of trying to generate enough warmth to make up for the loss which is occurring. The victim experiences difficulty in speaking, thinking, and walking. His judgment is impaired, and he may suffer from amnesia and hallucinations. Apathy, even lack of awareness concerning his situation, sets in.
- Late middle stages. By now (body temperature of 90.0 to 86.0) the victim has stopped shivering and has lost the ability to rewarm himself. He can no longer walk or speak. His muscles are rigid, his skin turns blue (cyanotic), and his pulse and respiration slow perceptibly. He passes into a state of stupor.
- Late stages. As the victim continues to cool (body temperature of 86.0 to 78.0), he becomes unconscious. He is non-responsive and his pulse and respiration may not be noticeable. A body temperature that falls below 78.0 degrees results in death, usually from a combination of heart and respiratory failure.
Early Detection and Avoidance of Hypothermia
The way to avoid hypothermia is, of course, through awareness and prevention. Put on proper clothing before you get wet, and take it off before you overheat and perspire.
Protect yourself from the cooling effects of wind, water, and cold surfaces. Be prepared to turn back from your objective or wait out a storm if necessary. Don’t be afraid to change your plan if a dangerous situation arises. Conserve your energy, eat and drink well, and don’t push too hard.
Watch for the telltale signs of hypothermia in others; some of us call them the “umbles”: stumbles, mumbles, fumbles, grumbles. Anyone exhibiting these behaviors is probably not well. It’s best to stop and deal with the situation before it progresses.
Treatment of Hypothermia
As soon as it becomes apparent that a member of the party is hypothermic, stop and check the rest of the group; if one person is exhibiting the symptoms, chances are high that others may be in the same condition. Stop traveling and set up camp immediately.
As with ice and avalanche rescue, these procedures must be rehearsed in advance of an actual emergency. Everyone must react quickly and efficiently. Set up the tents, build a fire, light the stoves, and heat the water. Meanwhile, someone must remain with the victim at all times and take charge of the overall situation.
Those in the early stages of hypothermia must have warmth, food, and fluids immediately. Get the victim out of wet clothes and into dry ones. Place him near a source of heat, such as a fire or another person. Putting the victim in a sleeping bag with another person works well as a rewarming strategy, but only if the nonhypothermic person is wearing light layers of dry clothing. If the rescuer is naked, his or her sweat will continue to chill the victim and may actually prolong the crisis.
If the victim is in the middle to later stages of hypothermia and is no longer able to rewarm himself, the rescuers must take even more active measures. The victim must be handled very gently in a controlled, protected environment, such as a tent. External sources of heat must be provided, and all possible heat loss must be stopped.
First, insulate the victim from the cold ground with sleeping pads, extra clothing, pine boughs, or whatever else is on hand. Place at the victim’s neck, groin, and underarms chemical heat packs or water bottles filled with warm water (not too hot to the touch). You can wrap the heat packs or water bottles in extra layers of long underwear or stuff sacks to keep them from burning or overheating the victim.
Place the victim in a prewarmed sleeping bag. Next, wrap him in a tarp, tent fly, or reflective blanket–whatever waterproof and windproof fabric is available–to cut heat loss through radiation and convection. If the victim is conscious, allow him to sip very sweet liquids, such as extra thick cocoa, liquid Jell-O, or some other supersweet instant beverage mix. The sugar will help replace energy reserves depleted by long bouts of shivering. Do not force liquids on an unconscious person.
If the victim lapses into unconsciousness or is lacking in all apparent vital activity, continue treatment and prepare for evacuation. Use extreme gentleness if you need to move him at all. Although this functioning may be undetectable, the heart may be operating at a very low level and any rough handling of the victim may cause it to cease altogether. There have been cases of apparently lifeless hypothermic individuals being successfully resuscitated with no lasting ill effects.
More from: The Winter Camping Handbook
• How to Winterize Your Vehicle
• Building Emergency Snow Shelters
Reprinted with permission from The Winter Camping Handbook (2016), by Stephen Gorman and published by Countryman Press.