With temperatures decreasing and winter sports on the horizon, schools should begin to consider the best ways to prevent cold weather injuries.
In addition to becoming familiar with environmental and non-environmental risk factors, schools should consider strategies for preventing and treating cold-weather injuries, as well as the school’s emergency action plan, policies and procedures regarding training in cold weather.
Making sure that coaches and athletes are equipped with all the necessary information is key to being prepared for a successful winter season.
Understanding that cold temperatures negatively affect the body’s regulatory system and that freezing temperatures are not required for athletes to sustain cold-related injuries are important to avoiding injuries and optimizing training conditions for athletes. In addition, windy and wet conditions increase the risk for cold-weather injuries.
Wind chill is the estimate of heat loss based on temperature and wind speeds. A lower wind chill may increase the rate of cold-weather concerns. Understanding how the body loses heat and the collaborative effect of temperature and wind/wet conditions are crucial to preventing cold-weather injuries.
The body loses heat through four mechanisms: evaporation, radiation, conduction and convection. Evaporation accounts for 15 to 25 percent of heat loss and occurs through sweating and respiration. Radiation is the normal process of heat moving away from the body. Increased blood flow to the skin’s surface combined with exposed skin can account for 50 to 65 percent of all heat losses from the body, with the most common places being the head, face, hands and neck.
Conduction is heat loss through direct contact with a cold surface. Sitting down in snow, ice or immersing in water for long periods of time causes heat loss until both the body and ground are the same temperature. Finally, convection is heat loss through the movement of air and/or water across the skin. Approximately 15 percent of heat loss is from convection and conduction; however, environmental factors such as snow, rain and high air speed in addition to inadequate clothing can increase this type of loss dramatically.
These four heat loss mechanisms are natural cooling processes that can become deadly in cold-weather sports without proper clothing, protection and awareness.
What are cold-weather injuries?
There are three categories used to classify cold-weather injuries: hypothermia, freezing-tissue injuries of the extremities and non-freezing injuries of the extremities.
Hypothermia occurs when the body is unable to maintain its core temperature and falls below 95 degrees (35C). This can occur quickly within a few hours or gradually over days and weeks. Conditions that may lead to hypothermia are cold temperatures, insufficient attire (clothing and equipment), wetness, poor nutrition, duration of event and exposed/uncovered skin.
Initially, individuals may feel cold, begin to shiver and be unable to perform motor function resulting in impaired athletic and mental performance. Early recognition of these symptoms is key to preventing more severe hypothermia. If early symptoms of hypothermia are not recognized or treated, the core temperature will continue to decrease.
More severe hypothermia symptoms include slurred speech, increased shivering, motor and coordination difficulties, and irrational behavior. The body’s inability to maintain a normal core temperature can affect the brain and nervous system, cardiovascular system, respiratory system and renal system, leading to cardiac and respiratory failure. If not treated quickly and appropriately, hypothermia can lead to death.
How to treat: Remove wet or damp clothing and insulate the individual with warm dry clothing and blankets. If possible, move the individual to a warm environment protecting them from further cold temperatures, wind and rain.
Frostbite occurs when tissues freeze. There are three distinct phases: frostnip, mild frostbite and deep frostbite. Frostnip is the stage prior to frostbite and occurs when the superficial skin cools below 50 degrees (10C). The skin becomes cold and red, and individuals feel a tingling painful sensation. Frostnip usually occurs in the nose, ears, cheeks, fingers and toes and does not cause longterm damage.
Mild/superficial frostbite occurs when skin temperature drops below 28 degrees (-2C) and superficial tissues freeze. Skin appears reddened initially and turns white or pale. Individuals may experience stinging, burning and swelling at the injury site. A fluid-filled blister may appear 12 to 36 hours after rewarming.
Deep/severe frostbite occurs when deep layers of skin are affected. Skin appears white or blueish gray and individuals experience numbness. Large blisters may form 24-48 hours after rewarming. The area will later turn black and hard as tissue dies.
Medical attention for frostbite is necessary when there are signs and symptoms of superficial or deep frostbite. Gently rewarm the area initially by wrapping the affected area in warm clothing. Do not rub the area.
Chilblain is a nonfreezing cold injury characterized by small itchy swellings on the skin that occur as a reaction to cold temperatures. Symptoms include the presence of small red bumps, swelling, tenderness, itching and pain. Treatment includes removing any wet or constrictive clothing and cover with dry warm clothing.
What are the risk factors for cold-weather injuries?
Non-environmental: Athletes can be predisposed to cold-weather injuries prior to going outside. Consider these risk factors for increased susceptibility to cold-weather injuries: nutrition and hydration, age, medications, body size and composition, fitness level, and clothing. Certain medical conditions may predispose individuals to cold injuries, including exercise-induced bronchospasm, Raynaud syndrome and cardiovascular disease.
Environmental: Environmental conditions such as cold temperatures and weather conditions can put added stress on the body. Prior to training or competing outside, review a variety of environmental conditions (air temperature, humidity, rain, snow and wind) to determine if it is safe for athletes. Wind-chill temperature index (WCT) indicates how cold a person feels when exposed to a combination of cold air and wind. The WCT is calculated through a formula, but multiple graphs and apps are available for quick reference. This index is a very useful and necessary tool to monitor the conditions individuals are exposed to during events held in colder weather. There are also guidelines for activity modification and when to postpone outdoor events. These guidelines should be included in a school’s or organization’s cold-weather policies and procedures and reviewed with all involved personnel.
Emergency Action Plan: The first step in preventing cold weather injuries includes reviewing the school’s Emergency Action Plan (EAP) and identifying specific cold-weather policies and procedures. The EAP should list and provide school with site-specific guidelines surrounding activities in cold weather as well as appropriate personnel to contact if there are concerns.
In addition, cold-weather policies and procedures provide specific information regarding cold-weather injuries and concerns most common in your local area, as well as identifiers to prevent injury and ensure safest participation for those involved.
Identify Risk Factors: Preparticipation exams aid in identifying individuals with a previous history of cold-weather injuries and/or known risk factors.
Education: Prior to the sport season, individuals should be educated on prevention, risks associated with cold-environment activity, and early recognition and treatment of cold injury.
Nutrition: Proper nutrition and hydration is equally important in cold-weather activities as training in cold-weather environments places an added stress on the body. Encouraging proper nutrition and hydration is key to maintaining optimal performance in cold-weather sports. Exposure to cold and shivering in an activity is fueled mostly by glycogen. This results in additional carbohydrate and caloric demands for participants.
Athletes are more prone to dehydration in cold-weather sports as the thirst reflex and desire to drink liquids may be lowered even though the hydration needs remain the same as training in optimal temperatures. Pre-practice/event and post-practice/event hydration is important and should focus on carbohydrate-based snacks. Depending on the outdoor winter activity, warm liquids served during a short break in activity can help rewarm the body from the inside out.
Clothing: Wearing sufficient layers of clothing around the body core is one of the most important considerations for preventing cold-weather injuries and should not be overlooked. Participants should wear appropriate attire for the conditions: long insulated pants, long-sleeve insulated shirt, gloves, face and ear protection, and socks that take the moisture away from the skin. Inner clothing layers should wick sweat and moisture away from the body and top layers should act as insulators, trapping heat and blocking the wind.
If athletes become wet during training or during competition, early recognition and intervention is important to preventing more advanced and dangerous stages of hypothermia. Immediately remove the athlete from the cold, take off the wet clothing and began rewarming the body slowly. Do not allow athletes to train for extended periods of time in wet clothing in cold weather.
Outdoor conditions can change rapidly, altering and shifting the body’s thermal balance and increasing the risk of cold-weather injuries. It is vital for administrators, coaches, athletes and their medical personnel to work together on prevention of cold-weather injuries. They should be aware of environmental conditions and risk factors; have an established and rehearsed EAP; ensure proper competition training, nutrition and clothing recommendations; and be willing to postpone or shorten events if weather factors indicate it is necessary. School leaders should take the time to discuss and implement some of these best-practice guidelines for cold-weather sports because safety of participants should always be the top priority.
Sallis R. Chassay C.M. Recognizing and treating common cold-induced injury in outdoor sports. Med Sci Sports Exerc. 1999;31 (10); 1367-1373
Cappaert, Thomas A, et al. National Athletic Trainers’ Association Position Statement: Environmental Cold Injuries. Journal of Athletic Training. 2008:43(6):640-658
Keller, Cary S. Guidelines for Competition in the Cold. NFHS High School Today. July 28, 2014
Castellani J.W, Young A.J, Ducharme M.B, Giesbrecht G.G, Glickman E, Sallis R.E. American College of Sports Medicine position stand: prevention of cold injuries during exercise. Med Sci Sports Exerc. 2006;38(11):2012-2029
National Weather Service. Windchill terms and definition. http://www.nws.noaa.gov/om/windchill/windchillglossary. shtml
Lynne Young, M.Ed, LAT, ATC, is a certified athletic trainer with nearly 25 years of experience. She is employed by Orthopedic Physicians Alaska and assists with outreach coverage to local schools in Alaska. She is a past member of the NFHS Sports Medicine Advisory Committee (SMAC).