Athletics in Extreme Cold: Dos and Don'ts

John D. Campbell, MD
Bridger Orthopedic & Sports Medicine
Bozeman, Montana

Wayne J. Sebastianelli, MD
Penn State Orthopaedics
State College, Pennsylvania

Participating athletically in cold, inclement weather can be a challenge. Athletes as well as caregivers can be subjected to significant thermal risk. It is important to recognize how quickly cold can interfere with bodily function. There are many historical reports of massive losses of military troops due to cold weather. Hannibal lost about half of his 46,000 troops while crossing the Pyrenean Alps in 218 BC. There are numerous other examples where exposure to the elements has changed the course of wars (and history).Most cold injuries today involve wilderness and sports enthusiasts, as well as the homeless.

Types of Cold
Wet cold occurs between 14°F and 50°F. This is the most dangerous type of cold environment. Temperature variations between melting and freezing make it difficult for people to dress appropriately. In addition, damp conditions from melting snow or rain makes keeping dry a challenge.

Dry cold occurs between 10°F and -20°F. Under these circumstances, the ground is frozen; hence snow will be dry and crystallized. Strong winds, if present, will create the most concern about remaining warm. Wind-proof outer garments, if possible, should be worn. Additional layers underneath will help buffer the wind.

Arctic cold occurs with temperatures below -20°F. This cold condition requires the most insulation and wind-proofing. The temperature can be so cold that some of the physical properties of the material may change and it may become more brittle. These types of conditions are only for the most experienced individuals.

Loss of Body Heat
The loss of body heat can occur in multiple ways. This includes radiation, conduction, convection, evaporation, and respiration.

• Radiation is the major source of heat loss. This is heat that is lost directly from exposed skin or the head. The head may lose up to one-half of the body’s total heat production at 40°F and up to three-quarters at 5°F.
• Conduction is responsible for approximately 15 percent of heat loss. Heat is lost through skin contact with cold objects, primarily through the hands or wet clothing.
• Convection is heat loss from the wind carrying heat away from the surface of the body. This is also known as the windchill effect.
• Evaporation accounts for approximately 21 percent of the loss of body heat via sweat, moisture from the skin, and air from your lungs. There is little that can be done to limit heat loss through evaporation.
• Finally, respiration is responsible for approximately 2 percent to 9 percent of heat loss. This occurs from inhaling cold air and exhaling warm air.

Cold Weather First Aid

Dehydration
Dehydration is defined as excessive loss of body water. To prevent dehydration during cold weather, athletes should drink at least two quarts of liquid a day. Dehydrating products such as caffeinated beverages should be avoided. At the first sign of concentrated, dark yellow urine, hydration should be increased.

Dehydration symptoms include tachycardia, dark urine or constipation, fatigability, thirst, headache, dizziness, cyanosis, and ultimately delirium. Treatment for mild cases of dehydration includes drinking warm liquids. More severe cases will require IV hydration.

Hypothermia
Accidental hypothermia, an extremely dangerous condition, is best described as the unintentional decrease in normal core temperature by at least 3.6°F or core temperature less than 95°F. More than 650 deaths from hypothermia occur in the United States each year. There are generally three categories:

• Mild hypothermia starts at 95°F. Most patients develop poor judgment and some may experience amnesia and tachycardia. At approximately 91°F, patients become ataxic and apathetic.
• Moderate hypothermia starts at 90°F. Patients exhibit stupor, loss of shivering thermogenesis, paradoxical undressing, loss of reflexes, and voluntary motion.
• Severe hypothermia starts at 79°F. This is the severe life-threatening stage. The lowest core temperature survived by an adult was 61°F.

To treat hypothermia, patients should have any wet clothing removed, and then be wrapped in heavily insulated materials. Warm sweet drinks without caffeine may also be given if the patient is awake. For unconscious patients, it is important to remember the high irritability of the heart; therefore, they should be moved very gently. If IV fluids are available, they should be warmed to 98.6°–106°F prior to infusion. Patients should be transported to an emergency room for a complete evaluation.

Prevention of hypothermia involves good planning and having the appropriate clothing. Athletes who are lost or tired from making camp should obtain warmth from the campfire as soon as possible.

Frostbite
Frostbite is actual freezing of tissue creating injury. Recovery is slow and severe frostbite can lead to gangrene and loss of tissue. Once tissue has been damaged by frostbite, it will be predisposed to frostbite in the future.

Predisposing conditions include prolonged exposure to temperatures below 32°F, brief exposure at extremely low temperatures (-25°F), exposed body parts, restriction of circulation, and a previous history of frostbite or other cold injury. Prolonged exposure to cold is more dangerous than brief exposure to very cold temperatures.

Frostbite symptoms include redness, pain, and mottled skin. With second-degree frostbite, there may be no pain, numbness, and difficulty in moving digits. Secondary blisters may appear. Third-degree frostbite includes full thickness injury to the skin. Pain will continue for several weeks after thawing. With fourth-degree frostbite, bone is also involved. Gangrene may develop and amputation may be necessary.

Treatment of frostbite should not include rubbing the area. The damaged site should be warmed as quickly as possible. Immersion into a warm water bath can be most effective. The temperature of this bath should be approximately 104°F. Do not attempt to thaw frostbitten limbs in the field. Recurrent cycles of freezing and re-warming should be avoided. It is less harmful for a victim to walk on the frostbitten limb than to thaw it out in the field and become refrozen during transport.

Prevention of frostbite includes proper clothing, nutrition, and the buddy system to check for abnormalities about the face, nose, and ears as well as the extremities.

Referral to a soft tissue treatment center familiar with the use of thrombolytic therapy can reduce the incidence of amputations. Tissue plasminogen activator (tPA) improves tissue perfusion when administered within 24 hours of the injury. This treatment modality represents the first clinically significant advancement in the treatment of frostbite in more than 25 years.

Frostnip and Chilblains
Frostnip occurs after superficial ice crystal formation associated with intense vasoconstriction. This usually resolves without any sequelae. With chronic intermittent exposure the patient may develop chilblains which are local areas of cyanosis, erythema, plaques, and possibly ulcerations. Treatment of these problems is symptomatic.

Snow Blindness
Snow blindness is caused by eye exposure to reflected ultraviolet rays of sunlight off the open field of white snow. Symptoms include the sensation of grittiness in the eyes, exacerbated by eye movement. The eyes may become watery and red. Headache and light sensitivity may also exist.

Treatment is to shield the eyes, even to include blindfolding. Further exposure should be avoided. If unavoidable, the eyes should be protected with dark bandages or dark sunglasses. Permanent damage is rare.

Prevention includes the use of sunglasses when any imminent danger of sun blindness is possible. Do not wait for the discomfort to begin.

Clothing Tips
The most important prevention point about cold weather is to remain dry. It is also important to remember that fatigue, hunger, and dehydration will lower the threshold for cold weather problems. Moisture will reduce the insulating properties of almost every fabric. Clothing should be worn in layers and should be kept as dry as possible.

Several layers of lighter clothing instead of one heavy layer are optimal. This will better insulate the body. Layers can also be removed easily if the temperature rises. Every attempt to remain dry should be carried out. Loose fitting clothing will optimize insulation. Wool is definitely better than cotton with respect to insulation. Appropriate socks and waterproof footwear will help keep feet maximally protected. The use of a hat will prevent heat escaping from the head, the largest source of heat loss over time.

Clothing layers

• Thermal underwear made of synthetic material
• Light shirt
• Sweater or light jacket
• Breathable waterproof outer layer
• Insulating socks made of wool or synthetic material
• Bootliners and insulated insoles
• Waterproof boots
• Head covering
• Gloves or mittens

Altitude
Above 6,000 feet, breathing and lack of oxygen to working muscles can limit performance even in the most highly conditioned athletes. Common symptoms of altitude illness include headache, nausea, and fatigue. The condition can also affect sleep and rest due to shortness of breath.

For those participating in athletics or caring for athletes at high altitude, the following tips can be helpful:

1. During the first day in altitude, try to perform some light exercise.
2. Get plenty of rest even if having difficulty sleeping.
3. If possible, use a humidifier in the living quarters.
4. Eat smaller, but more frequent meals. Plenty of carbohydrates and fluid are required.
5. Take deep breaths as often as possible.
6. Avoid alcohol for the first 1–3 days.
7. Frequent rest breaks are necessary.
8. Drink more water than thirst dictates.
9. Try to train as much as possible prior to the high altitude endeavor. In addition, the use of Diamox started prophylactically approximately 2–3 days prior to the trip can be helpful. The typical dose is 250mg 3–4 times a day continued for the first 24 hours after arriving at the destination.
10. Avoid rapid ascent. Sleep no more than 1,500 ft. higher each day above 10,000 ft.

References
Bruen KJ, Ballard JR, Morris SE, et al. Reduction of the incidence of amputation in frostbite with thrombolytic injury. Arch Surg. 2007;142:546-553.

Casa DJ. Performing in extreme environments. J Athl Train. 2000;35:111-112.

Biem J, Koehncke N, Classen D, Dosman J. Out of the cold: Management of hypothermia and frostbite. Can Med Assoc J. 2003;168:305-311.

Jurkivich, GJ. Environmental cold induced injury. Surg Clin North Am. 2007;87:47-67.

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