Cold Injuries - Types, Symptoms, Risk Factors, First-Aid Management, and Prevention

Introduction

Cold injuries result from exposure to cold environments during physical activity. Many athletes engage in year-round fitness pursuits and physical activity, often encountering cold, wet, or windy conditions, or a combination thereof, which increases their risk of cold-related injuries. Cold exposure not only causes discomfort but also hampers performance and can even be life-threatening. Military personnel, participants in traditional winter sports, and participants in outdoor sports, including running, cycling, hiking, and swimming, are the main groups at risk for cold-related injuries and diseases. Additionally, traditional team sports like football, baseball, softball, soccer, lacrosse, and track and field have seasons that extend into late fall or early winter, or commence in early spring, further exposing athletes to the potential vulnerability of cold injuries.

The National Athletic Trainers' Association (NATA) policy statement claims that low air or water temperatures, as well as the effect of wind on the body's capacity to maintain a normothermic core temperature, all affect the likelihood of severe injuries. This is a result of the extremities being exposed locally to cold surfaces or air.

What Are the Types of Cold Injuries?

Cold conditions are a common occurrence in alpine environments, where open and exposed areas such as mountain peaks often experience windy conditions that intensify the cold temperatures, known as the 'wind chill factor.' These conditions collectively result in heat loss, placing additional demands on the body. Even a slight decrease in core body temperature, as little as 1°C, can trigger muscle shivering, leading to reduced sporting performance due to low blood glucose levels (hypoglycemia). Cold injuries can be broadly categorized into three types:

Hypothermia: Hypothermia occurs when the body's temperature drops significantly below 95°F (35°C) due to an imbalance between heat loss and heat production, leading to an inability to maintain a normal core body temperature. This can happen rapidly within a few hours or gradually over days and weeks. Factors contributing to hypothermia include cold temperatures, inadequate clothing and equipment, wetness, poor nutrition, prolonged exposure, and exposed or uncovered skin.

A useful tool for determining how chilly someone feels when exposed to cold air and wind is the Wind-Chill Temperature index (WCT). It is calculated using a formula, and there are multiple graphs and apps available for quick reference. The Wind-Chill Equivalent Index (WCEI) demonstrates that wind speed, when combined with ambient temperature, significantly enhances body cooling. Furthermore, the cooling effect is boosted by the evaporation of liquid trapped next to the skin by wet clothing if the body and clothing are wet from sweat, rain, snow, or immersion.

Immersion Hypothermia From Cold Water Immersion: Immersion hypothermia is a unique illness brought on by exposure to cold water. As water transfers heat away from the body 25 times faster than air, it develops significantly more quickly than typical hypothermia. The majority of people in temperate climates do not believe they are at risk for hypothermia in the water, but it can happen in any water that is below 70°F. By using a personal flotation device (PFD, life vest, immersion suit, or dry suit), dressing appropriately (wool and synthetic materials rather than cotton), using a PFD, and having a means of both signaling rescuers and being retrieved from the water (strobe lights, personal locator beacons, whistles, flares, waterproof radios), one can extend their chances of surviving.

Freezing Injuries of the Extremities: In situations of prolonged exposure to cold, the body responds by constricting blood vessels in the hands and feet, diverting blood flow to vital organs to prevent a further drop in internal body temperature. This protective mechanism, however, causes the toes and fingers to progressively become colder, leading to injury in the affected tissues. Water within the tissue crystallizes as a result of changes in electrolyte concentration within cells, causing frostbite damage. Tissue temperature must be below 28°F (-2°C) for cells to freeze. The severity of frostbite is determined by the duration of exposure and is categorized into three degrees based on the depth of tissue injury.

Frostnip: Frostnip is the preliminary stage preceding frostbite, characterized by the cooling of superficial skin below 50°F (10°C). The skin becomes cold and red, accompanied by a tingling, painful sensation. Frostnip commonly affects the nose, ears, cheeks, fingers, and toes but does not cause long-term damage.

• Mild or Superficial Frostbite: Superficial frostbite occurs when skin temperature drops below 28°F (-2°C), leading to the freezing of superficial tissues. Initially, the skin appears reddened and then turns white or pale. At the site of the damage, people may feel stinging, burning, and swelling. After rewarming, fluid-filled blisters may develop within 12 to 36 hours.

• Deep or Severe Frostbite: Deep frostbite occurs when deep layers of skin are affected. The skin appears white or bluish-gray, and individuals experience numbness. Large blisters may develop 24 to 48 hours after rewarming. Over time, the injured area will turn black and become hardened as the tissue dies.

Reported rates of hypothermia and frostbite in mountaineers are approximately three percent to five percent of all injuries and 20 percent of all injuries in Nordic skiers. In military personnel, the frequency of cold injuries ranges from 0.2 to 366 per 1000 exposures.

Non-freezing Injuries of the Extremities:

• Chilblain: Chilblain, also known as pernio, is a non-freezing cold injury that occurs after prolonged exposure (one to five hours) to cold and wet conditions. The severity of chilblain is influenced by time and temperature. Higher water temperatures (ranging from 32°F [0°C] to 60°F [16°C]) require longer exposure duration to develop chilblain. Exposure time for chilblain is typically measured in hours or even days, as opposed to the shorter durations associated with frostbite. Chilblain is characterized by an abnormal inflammatory response to cold exposure, resulting in prolonged constriction of skin blood vessels, hypoxemia, vessel wall inflammation, and dermal edema. It can occur with or without tissue freezing and commonly affects the hands, feet, and occasionally the thighs. Alpine sports, mountaineering, hiking, endurance sports, and team sports with prolonged wetness from water exposure or sweating can contribute to chilblain occurrence.

• Immersion (Trench) Foot: Immersion foot typically occurs with prolonged exposure (12 hours to four days) to a cold and wet environment, typically in temperatures ranging from 32°F to 65°F (0°C to 18°C). It primarily affects the soft tissues, including nerves and blood vessels, due to an inflammatory response that results in increased extracellular fluid. The main cause of trench foot is prolonged wearing of wet socks or footwear.

What Are the Signs and Symptoms of Different Types of Cold Injuries?

Hypothermia: Depending on how long people are exposed to cold temperatures, hypothermia symptoms can change.

The earlier signs of hypothermia include:

• Shivering.

• Fatigue.

• Inability to coordinate.

• Disorientation and confusion.

The late signs and symptoms of hypothermia include:

• No trembling.

• Colored skin.

• Dilated eyes.

• Slowed breathing and pulse.

• Consciousness loss.

Frostbite:

The mid or superficial signs of frostbite include:

• Dry, waxy skin.

• Erythema (redness).

• Edema (swelling).

• Transient tingling or burning sensation.

• The skin contains white or blue-gray patches.

• The affected skin feels cold and firm to touch.

• Limited movements of the affected area.

The deep signs of frostbite include:

• Skin is hard and cold.

• The skin may appear waxy and immobile.

• Skin color is white, gray, black, or purple.

• Presence of vesicles (blisters).

• Burning, aching, throbbing, or shooting pain.

• Poor circulation in the affected area.

• Progressive tissue necrosis (death of tissue).

• Neurapraxia (temporary nerve damage).

• Hemorrhagic blistering develops within 36 to 72 hours.

• Likely damage to muscles, peripheral nerves, and joints.

Chilblain or Pernio:

• Red or cyanotic lesions.

• Swelling.

• Increased temperature.

• Tenderness.

• Itching, numbness, burning, or tingling.

• Skin necrosis (tissue death).

• Skin sloughing (shedding).

Immersion (Trench) Foot:

• Burning, tingling, or itching sensation.

• Loss of sensation.

• Cyanotic or blotchy skin.

• Swelling.

• Pain or sensitivity.

• Presence of blisters.

• Skin fissures or maceration (softening due to prolonged moisture).

What Are the Risk Factors for Cold Injuries?

When blood flow is restricted, not enough food is consumed, and not enough oxygen is accessible, as is the case at high altitudes, there is an increased risk of cold injuries. It is separated into the following two groups:

• Non-environmental: Before stepping outside, athletes are frequently vulnerable to cold-weather injuries. Age, medications, body size and composition, degree of fitness, nutrition, and hydration, as well as clothing, are risk factors for an increased vulnerability to cold-weather injuries. Athletes who have certain medical disorders, such as Exercise-Induced Bronchospasm (EIB), Raynaud syndrome, and cardiovascular disease, are more likely to sustain cold-related injuries.

• Environmental: The body may be put under additional stress by environmental factors like frigid temperatures and bad weather. Examine numerous climatic factors, such as air temperature, humidity, rain, snow, and wind, to evaluate whether it is safe for athletes to train or compete outside before doing so.

What Is First Aid Management for Cold Injuries?

Hypothermia: To effectively treat a worker with hypothermia, follow these steps:

• Alert the supervisor and promptly request medical assistance.

• Move the victim into a warm room or shelter to protect them from further cold exposure.

• Remove the wet clothing from the victim.

• Prioritize warming the central areas of their body, starting with the chest, neck, head, and groin. Use available resources like an electric blanket or provide skin-to-skin contact under loose, dry layers of blankets, clothing, towels, or sheets.

• Offer warm beverages to the victim as it may aid in increasing their body temperature. However, do not provide alcoholic beverages. Note that this step is not suitable for an unconscious person.

• Make sure the person stays dry and put them in a warm blanket that covers their head and neck after their body temperature starts to rise.

• If the victim shows no signs of pulse or circulation, initiate cardiopulmonary resuscitation (CPR) immediately.

Frostbite: For workers suffering from frostbite:

• Immediately seek shelter in a warm room.

• If possible, refrain from walking on frostbitten feet or toes to prevent further damage.

• Immerse the affected area in warm water, ensuring the temperature is comfortable to the touch for unaffected body parts.

• Utilize body heat to warm the frostbite area. For instance, tuck frostbitten fingers in the warmth of an armpit.

• Avoid rubbing or massaging the frostbite area, as it can cause additional harm.

• Avoid warming the affected areas with heating pads, heat lamps, stoves, fireplaces, or radiators since they are numb and prone to burns.

Trench Foot: For workers suffering from trench foot:

• Remove shoes or boots and wet socks immediately.

• Thoroughly dry the feet.

• Avoid putting weight or walking on the affected feet to prevent tissue damage.

Chilblains: For workers suffering from chilblains:

• Never scratch the injured region.

• Gradually warm the skin.

• Consider using corticosteroid creams to alleviate itching and swelling.

• Keep blisters and ulcers clean and protect them with appropriate coverings.

How Can Cold Injuries Be Prevented?

To prevent cold-related injuries, effective planning, adequate preparation, and proper equipment usage are crucial. The following strategies are discussed below.

• Education: Inform athletes on ways to avoid becoming hurt or ill from exposure to the cold. Prior to the sports season, provide education on prevention techniques, risks associated with cold-weather activities, and early recognition and treatment of cold injuries. Sports medical staff and coaches should be aware of individuals with conditions that may increase their teams' vulnerability to cold-related risks, such as predisposing medical conditions, physiological factors, mechanical factors, and environmental conditions.

• Hydration: Recognize that athletes in cold-weather sports are susceptible to dehydration, as the thirst reflex and desire to drink may be reduced despite the need for adequate hydration. Emphasize pre-practice and post-practice hydration, focusing on carbohydrate-based snacks. Depending on the outdoor winter activity, serving warm liquids during short breaks can help rewarm the body from the inside out.

• Nutrition: For cold-weather exercises, proper nutrition is crucial because training in cold conditions stresses the body. Promote proper nutrition to maintain optimal performance in cold-weather sports. Cold exposure and shivering during activity primarily rely on glycogen, increasing the demand for carbohydrates and calories in athletes.

• Clothing: Pay close attention to wearing adequate layers of clothing around the body core, as it is crucial for preventing cold-related injuries. Advise individuals to dress in layers and aim to stay dry. Adjust the number of layers based on temperature, activity levels, and wind chill.

• Energy: Maintain energy levels by consuming balanced meals, energy snacks, and carbohydrate or electrolyte sports drinks, as a negative energy balance increases susceptibility to hypothermia.

• Warm-Up: Perform a thorough warm-up and maintain warmth throughout the practice or competition to minimize decreases in muscle or body temperature. Time the warm-up to lead directly into the competition. After the competition, add clothing layers to prevent rapid cooling.

Conclusion

In conclusion, cold injuries pose a significant risk in cold environments during physical activity. These injuries can range from mild discomfort to severe tissue damage and can have long-term consequences. Prevention is crucial, and individuals should prioritize education, proper hydration and nutrition, suitable clothing, and adequate warm-up. Recognizing the signs of cold injuries and seeking prompt medical attention is essential. By taking these precautions, individuals can reduce the likelihood of cold-related injuries and ensure their safety in cold environments.