Hiking at Altitude: Mountain Maladies
High altitude hiking may face you not only with the dangers of altitude illness but also with various heat and cold-related conditions. Trekking and travel through places with high altitude brings changing weather conditions and environments from extreme cold, snowy and windy heights to extreme heat as both can happen on the same trek.
Heat and UV radiation-related conditions
You know that intense ultraviolet radiation (UV) from the sun is dangerous, however, you probably don’t know that UV radiation increases up to about 20% for every 1000m above the sea. Thus, everyone who hikes at altitude is exposed to more UV radiation and as a consequence to burn injuries from overexposure to UV radiation. Moreover, when reflected off snow and ice, UV radiation is even more serious threat to unprepared people in the mountain.
There are various potentially dangerous heat-related conditions as some of them are typical of summer hiking. The main cause for these conditions is the heat that builds up by extreme exertion or by exposure to hot conditions. Often this heat cannot be released through the skin because high humidity slows evaporation and impairs heat dissipation. There are two major kinds of heat illness - heat exhaustion and heatstroke as the former is milder compared to the latter.
Table 1: Environmentally related conditions and injuries associated with hiking at altitude
Source: Mountaineering: The Freedom of the Hills*
Heat exhaustion affects mainly the elderly, dehydrated or salt-depleted individuals, people who aren’t acclimatized to hot climate, and people who cannot sweat properly like those taking medications that interfere with the skin’s ability to release heat through producing moisture. The main symptoms of heat exhaustion include headache, faintness, lassitude, thirst, dizziness, nausea, vomiting, rapid pulse and heart rate, and cool and clammy skin. The reason for these symptoms is the inadequate blood supply to the brain and other vital organs caused by the shunting of blood to the skin.
Prevention includes proper hydration (rest in the shade during the hottest part of the day), acclimatization (usually takes around a week), wearing light-colored clothing and covering the head, and soaking hats and clothes in water to cool the body.
Treatment includes rest (preferably in the shade), proper hydration through drinking plenty of drinks and electrolytes, salt, reduced clothing, and pouring water over the head, body, and clothing to promote cooling.
Heatstroke, also called sunstroke, is a failure of the heat regulation process of the body and is a life-threatening situation. As a result of exhaustion of the sweat glands, the body core temperature rises to 41°C or higher, which causes the victim to feel extremely hot. An ordinary person starts sweating to release the build-up heat through evaporation, however, the skin of an individual with this condition feels hot and dry but does not sweat. What can follow is confusion, deteriorating coordination, delirium or coma. The main and most reliable symptom is altered mental state, including confusion, incoherent speech, uncooperativeness, irritability, combativeness, and delusions. Some other symptoms of a heatstroke include:
- Rapid pulse and breathing
- Flushed, hot skin
- Loss of coordination
If someone has become a victim of a heatstroke, you need to remove the clothing that retains heat and cool them immediately. You can do the following steps:
- Immerse the victim in water or ice. Pack them in snow if you’re in the mountain and do not have an access to ice or water. Remember that you need to cool them as soon as possible by any means.
- Massage the limbs to promote the circulation.
- Cool until the body temperature drops to 39°C.
- Monitor the temperature, mental status, and general condition in the next a few days. Keep in mind that the temperature may increase again; if this happens, start cooling again.
Sunburn is a skin injury that's common among hikers and climbers visiting high altitudes. That's because “thin air, less UV protection”. Moreover, clouds do not filter UV radiation effectively so your skin can burn even on a cloudy day. Furthermore, snow and ice reflect the sun’s rays, which increase the radiative heat transfer.
There are three types of burns depending on the severity of the burn:
- First-degree burns - superficial; cause redness of the skin; damage tissue but do not kill it.
- Second-degree burns - cause blisters; kill the upper portion of the skin.
- Third-degree burns - kill not only the skin but also the underlying tissue.
The best prevention is provided by covering the exposed areas of the body (skin) with clothing. Clothing filters UV radiation effectively so the skin does not burn. Certainly, not all clothing does the same job as the screening ability of garments depends on the weave. Though tight weave is hotter to wear, it protects better against UV radiation. Lightweight hiking clothes with UPF rating are specially developed to protect from the sun’s ultraviolet rays. Sunscreen products also work well, especially when properly applied.
Sunburn is like any other burn so there is no need for a special treatment. For milder burns cool the burned area, cover it, and treat it for pain. And… that’s it. For more serious sunburns, you need to wash the area gently with cold water. Then cover it with a sterile dressing. Meanwhile, drink plenty of fluids. You can relieve the pain with antibiotic ointment. Hence, if you have some, use it before covering the burnt skin with a dressing. For serious cases, two tablets of aspirin and codeine every six hours may help you relieve pain.
When the outer layers of the eyes are burned by ultraviolet radiation, the so-called snow blindness occurs. It’s a temporary condition that sets in 6-12 hours after radiation exposure. The first symptoms are dry and light-sensitive eyes that become reddened and teary. This is followed by severe pain in the eyes.
There are several methods for the prevention of snow blindness. Sunglasses with UV-protective lenses are indispensable for high altitudes. They will protect your eyes from the UV radiation. Polarized layers on the lenses help where reflection is especially intense. If you lose your glasses, you can craft goggles from duct tape or cardboard by cutting horizontal slits for each eye. Sherpas and Tibetans’ favorite method is hair combed over the face.
Common treatment of snow blindness includes: 1) use drugs that offer pain relief; 2) cool compresses and darkness also help for pain relief; 3) cover your eyes with sterile dressings and padding to prevent irritation from eyelid movement. The condition resolves after a day or two, however, sometimes it may take up to a week.
Heat and UV radiation-related conditions are among the most prevalent mountain maladies, though cold-related conditions probably occur even more often. Cold-related illnesses occur when an individual loses more body heat than the body can restore. The four main mechanisms of the heat loss to the environment are the following: convection, radiation, conduction, and evaporation. See our post about cold weather hiking clothing for more in-depth information about these mechanisms.
Three cold-related conditions pose the main threat in the mountains: hypothermia, frostbite, and immersion foot. Hypothermia affects the entire body and can be deadly, while frostbite and immersion foot are localized in their effects.
As we highlighted in our post about hiking in the rain, hypothermia is a dangerous condition that kills many hikers, travelers, climbers, and others every year. Hypothermia is a potentially deadly condition that occurs when the core body temperature drops to 35°C or less. This temperature drop comes up when the total amount of body heat released exceeds body heat produced. Thus, this cold-related condition can develop and kill at temperatures above freezing.
It comes as no surprise that hypothermia is often termed exposure. Although many people would suggest that hypothermia comes as a result of exposure to extreme cold, it actually is a result of prolonged exposure to chilly environments often combined with wet clothing and/or exposure to wind. Dehydration, inadequate nutritional intake, high altitude, insufficient clothing, and exhaustion are some other factors that can facilitate and accelerate the occurrence of hypothermia. Trekkers practicing high altitude hiking must be prepared to prevent hypothermia. Knowing its symptoms and signs can help you recognize them on time so that you may be able to prevent the development of hypothermia. Before continuing with the main symptoms and signs of this cold-related illness, we should note that children and small adults are especially prone to hypothermia. So, be careful when hiking with kids in the mountains. What’s interesting is that obese people have an advantage over slim individuals because their fat provides them with better insulation. In addition to the natural insulation provided by your body fat, you can also insulate your body against the cold by using a layered clothing system consisted of a base layer, fleece, and waterproof breathable jacket. Good hiking boots, hat, warm and waterproof gloves add another layer of protection.
The initial symptoms of hypothermia often remain unnoticed or are neglected. They’re the following:
- Marked shivering
- Pale skin
- Fumbling hand movements
The symptoms of severe hypothermia include:
- Shivering stops
- Stiff muscles
- Decreased pulse and respiration
- Uncoordinated movements
- Irrational behavior and memory lapses
- Slurred speech
All these symptoms and signs are followed by the final phase of hypothermia that leads to unconsciousness and death. Keep in mind that the situation can quickly exacerbate and progress from the initial symptoms to the point where the victim cannot perform the functions necessary for survival.
To prevent hypothermia you must: have adequate insulation and avoid being wet, avoid being exposed to the wind, stay well fed and hydrated, and pace yourself to avoid excessive sweating and exhaustion.
Mild hypothermia can be treated by stopping further heat loss by applying heat to the victim’s body. Best way to do that is by removing all wet clothing and placing the person in a sleeping bag together with a source of heat - hot water bottles at the chest, under the armpits, and around the groin, warmed rocks wrapped in cloth or a warm person. If the person is conscious, you can give him warm drinks and later sugar-based foods. Note that rehydration is more important than giving warm drinks.
For cases of severe hypothermia (and generally for people with a body temperature below 31°C), quick evacuation is needed. People with severe hypothermia need gentle rewarming to avoid rewarming shock. Because of the low temperature of such a person, he may show no signs of life and appear dead. Remember the saying “no one is dead until warm and dead” and don’t give up on resuscitation efforts until the person is warm and still shows no signs of life.
Once back to normal temperature, the severe hypothermia patient must be monitored just like someone with heatstroke because temperature-regulating mechanisms may not be stable for a considerable amount of time.
Frostbite is the freezing of the blood vessels surrounding tissues of body parts such as fingers, toes, ears, noses, and chins. This condition is most common among alpinists (because of the temperature extremes they’re exposed to) and occurs rarely in hikers, though it can happen on high passes and trekking summits where trekkers may encounter low temperatures for long periods of time. As a result of frostbite, blood vessels can be temporarily or permanently damaged. In the early stage blood cells clump in a reversible way, while tissues become cold, painful, and pale. After prolonged freezing, these clumps may become a permanent problem with serious consequences, especially since the affected individuals don’t feel the affected extremities and forget about the problem. Keep in mind that frostbitten tissue is damaged and fragile and should not be massaged.
The best prevention is through wearing adequate footwear, clothing, gloves and mittens, and equipment. Eating enough food, avoiding dehydration and exhaustion, and experience also help a lot in preventing frostbites. Avoid constricting boots, skin contact with cold metal, and keep your feet dry. Stop and warm your fingers and toes while they are still causing tingling and pain before they go numb. High altitudes, significant wind, tight boots that restrict blood flow, exhaustion, and previous history of the problem can increase the potential for frostbites.
Before giving any treatment, try to assess whether field rewarming is appropriate or desirable (it can be very difficult to decide whether the injury is reversible or not). Treatment of frostbites in initial stage consists of rapid rewarming of the affected extremity by placing it against a warm area of the body (armpit, hand, stomach etc.) of the victim or another hiker. When the part restores its color, feeling, and consistency, it can be used given that it is not allowed to freeze again. Be careful, because if that happens, the line of tissue death will probably extend to the refreeze line. Ibuprofen or aspirin can provide temporary pain relief. A frostbitten foot should be kept frozen until help and safety has been reached because once thawed, it will be impossible to walk on. In the rare case when field rewarming is considered advisable, do it in a water bath with a temperature between 38°C and 42°C. Be very careful and don’t use hot water because the frostbitten part is extremely susceptible to thermal injury. Such a rewarming procedure will probably cause blisters. If still in the wilderness, wash gently, cover with sterile dressings, and leave it alone in order to reduce the risk of infection.
This condition is a kind of trauma to nerves and muscles caused by reduced oxygen distribution. It occurs when a person’s feet have been wet and cool for long periods and affects mainly those who neglect to dry and warm their feet at night, especially after hiking or climbing day after day.
The main symptoms and signals are pale, pulseless, tingling feet. Treatment includes careful rewarming in a water bath slightly warmer than body temperature (don’t use too warm or hot water because the immersion foot can lead to gangrene). During rewarming, your legs will become reddened and swollen, with bounding pulse because they’re congested with blood. This can be very painful. The recovery period is several days, however, keep in mind that the immersion foot may recur.
High altitude hiking can be a very dangerous activity because you are exposed to the elements often without shelter. Thus, you must be acquainted with the dangers that await you when crossing the mountains. Many people, especially novice backpackers, consider that the only dangers up in the mountains are linked to the altitude illness and cold-related conditions such as hypothermia or frostbite. However, hiking at altitude brings all kinds of environments from extreme cold to extreme heat and everyone who’s interested in treks at high elevations must be familiar with the cold, heat and UV radiation-related conditions, their symptoms, signals, and the dangers they pose as well as prevention and proper treatments. Remember that prevention is better than cure and try to always apply this principle on the trail.
* In R. C. Eng. (Ed.), Mountaineering: The Freedom of the Hills, 8th ed., 2010, The Mountaineers