Don't Get Sick on the Trail

Four factors loom large in illnesses when you’re hiking — poor judgment, inclement weather, inadequate clothing, and faulty gear.

Recently, the Centers for Disease Control and Prevention ranked hiking as the third most dangerous outdoor recreational activity, based on injuries reported by 63 U.S. hospitals.

While hiking comprises just 6.3 percent of all outdoor sports and recreational accidents, as published in Wilderness and Environmental Medicine, it’s worth knowing that many of these ailments can be prevented. Poor weather, inadequate clothing, and faulty gear contribute to many trail illnesses.

The best advice for healthy hiking? With weather—don’t push your luck. An experienced leader, faced with bad weather, knows when to turn back, even short of a goal. This includes heavy winds, rain, lightning, and blizzards.

Update and maintain your equipment. This includes clothing, shelter, stoves, and boots. Always match your equipment list to the terrain and environment you’ll be hiking through.

The following five conditions can turn a trip of a lifetime into a fight for your life. All of them are more easily prevented than cured, and all of them are potentially fatal medical emergencies. Simple planning and “being prepared” can turn the odds in your favor.


Most people equate dehydration with hot weather and heat-related ailments such as heat stroke. Dehydration can also contribute to hypothermia and altitude sickness. In fact, drinking enough water is probably the No. 1 way to keep you healthy—in cold and hot weather.

Prevention: Never skimp on water. Drink as much as you can before you start hiking, and continue drinking regularly. Use maps, guidebooks, and current local information from rangers to find out where the water sources are and how reliable they are. In dry or desert environments, drink at every water source and carry extra water so you won’t go dry. In cold weather, cook up hot drinks to make hydration more appealing.

Symptoms: Thirst, dark-yellow urine, dizziness, headaches, nausea and vomiting, and—later—unconsciousness.

Treatment: Cool down, rest, and drink. Use electrolyte-replacement drinks or a homemade version consisting of a tablespoon of sugar and a half teaspoon of salt in a liter of water.


Closely related to dehydration are heat exhaustion and heat stroke.

Prevention: Drink often, take plenty of shade breaks, don’t push too hard, walk in cooler parts of the day, take advantage of streams and lakes for a quick temperature-reducing dip, and, on a long hike, take it easy until your body has had time to acclimate to heat. Wear well-ventilated clothing that covers your skin.

Symptoms: Dizziness, light-headedness, confusion. Heat exhaustion victims will be sweaty and clammy. In heat stroke, victims will be flushed but dry and hot to the touch. Heat stroke symptoms also include fever, seizures, rapid heartbeat, and loss of consciousness.

Treatment: Place the victim in the shade, covered with water or with towels and clothes soaked in cool water. Treat for shock. Administer water or electrolyte-replacement drinks, and seek medical attention.


Hypothermia, an insidious threat, often goes unrecognized until it becomes an emergency. You don’t have to experience snow camping in Siberia to be at risk. Hiking on a 50-degree day with occasional rain showers or rafting on a cold river can be equally dangerous.

Prevention: Drink frequently, even if you don’t feel thirsty. Check your gear (hats and gloves, especially). Note early signs of chill, such as shivering, and reduce or eliminate your exposure immediately, especially in wet conditions. Drink hot liquids or build a fire.

Symptoms: The “umbles” (stumbles, mumbles, fumbles, grumbles). Shivering stops, but the body temperature is cold. Also, fatigue, forgetfulness, irrationality, staggering, and unconsciousness.

Treatment: Eliminate exposure (put up a tent, get out of the elements, sit on an insulating pad, get into a sleeping bag), make a hot drink, and gently warm the victim. Hikers are far more successful at preventing hypothermia outdoors than curing it. A severe case will require an emergency rescue evacuation.


Altitude sickness is a result of traveling or climbing too high too fast: The body doesn’t have time to adjust, and symptoms progress from a headache to life-threatening edemas (swelling of the lungs and brain). Altitude sickness strikes different people at different elevations, but most people feel some effects at elevations above 10,000 feet.

Prevention: Hike high, camp low. Hiking higher exposes your body to the new elevation; camping low lets you adjust to it. On climbs where this is not possible, limit your net elevation gain to no more than 1,000 feet per day (once you’re above 10,000 feet). The drugs Diamox and, believe it or not, Viagra are commonly used to help prevent high-altitude sickness. They must be prescribed by a physician and taken as directed.

Symptoms: Above 10,000 feet, assume that any unusual symptoms are the result of altitude. Common early symptoms are loss of breath, headaches, sluggishness, loss of appetite, and nausea. More serious symptoms include disorientation, staggering, irrationality, loss of balance, and, finally, pulmonary and cerebral edemas.

Treatment: Treat the early symptoms and you won’t have to deal with the later ones. You can wait out the minor symptoms and see if you acclimate—many people do—after taking a rest day. If symptoms persist or worsen, returning to a lower elevation is the only treatment.


Ironically, this condition can occur in the same hot weather that causes heat-related illnesses. Drinking too much water, often in conjunction with excessive sweating, causes hyponatremia. Sweating causes the loss of salts and electrolytes. The imbalance makes it impossible for the body to properly function. Untreated, a serious case can lead to kidney (and other organ) failure.

Prevention: Scale it down a notch. In hot weather, cut back your mileage and pace and take plenty of rests. Most important: Snack frequently, whether you’re hungry or not, to replace the electrolytes. One of the best snacks is a handful of mixed nuts, fruits, and banana chips, which contain salts, sugars, and potassium.

Symptoms: Early symptoms occur when you drink a lot but still experience persistent thirst. Other symptoms include urinating frequently, excessive sweating, nausea, vomiting, and headaches.

Treatment: A mild case of hyponatremia can be treated with rest, food, and electrolyte-replacement drinks. Sauces with salts replace the electrolytes. More severe cases require medical attention.

Karen Berger is the author of Backpacking and Hiking (BSA No. 34354, $20). Visit her Web site



  1. As a Scout I learned skills for hiking that have help through my adult life. As a Scouter for more than 30 years ( 16 as a Scoutmaster and 7 as a Venture Advisor) I feel that first aid and hiking skill are very important for our Scouts to learn and practice often until the become somethin natural to them. We enjoy the outdoors very much and we are lucky to live in a tropical island ( Puerto Rico) we go camping once a month and put to practice this skills. Thanks for all the information we receive from your articles we keep updating our teaching skills. Gracias y que Dios los bendiga! ( Thanks and God bless you!)

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