There are three common types of cold weather injury. Cold weather injury prevention is an essential part of preparing for outdoor activities in the winter. The three significant injuries of which to be concerned while enjoying your outdoor adventure are frostbite, hypothermia, and immersion/trench foot. By far, frostbite and hypothermia are the injuries that gain the most attention in the survival literature. However, immersion/trench foot also is a cold weather injury. There are several factors to keep in mind when assessing risk for getting a cold weather injury. Here are some risk factors to consider before heading outdoors:
- Temperature: What are the current and projected temperatures?
- Humidity: What is the current and projected humidity levels?
- Wind Chill Factor: What is the current and projected wind chill factor? Do I have my wind chill factor assessment card?
- Previous Cold Weather Injury: Have I or anyone in my group had a previous cold weather injury?
Frostbite is the condition in which the exposed skin tissues of the body begin to freeze (“Frostbite,” WebMD, 2019). The most likely people to get frostbite while outdoors in the winter are people typically men between 30-49 years old. The reason is that men are the largest demographic that spends the most time outdoors throughout the year. The parts of the body that tend to get frostbite are nose, cheeks, ears, forehead, chin, wrists, fingers, and toes (FM 4-25.11, 2002, 5-11). There are two basic categories of frostbite: superficial and deep. Furthermore, there are four stages or degrees of frostbite: normal, frostnip, superficial frostbite, and deep frostbite (“Understanding Frostbite–The Basics,” WebMD, 2017), (“Frostbite,” Mayo Clinc.org, 2018).
Kamler writes the following, “When heat production can no longer fend off the cold, the body conserves its warmth by constricting blood vessels in the areas that leak the most heat. Hand and feet, noses and ears become pale and cold.” (Kamler, Surviving The Extremes, 2004, 199). Consequently, these parts of the body become subject to frostbite very quickly by continuous exposure to cold temperatures.
Moreover, I remember being stationed at Fort Riley, Kansas in the winter of 1989, when one of our African-American sergeants passed me by in the motor pool. I noticed that he had an incredibly vivid white spot on his nose near his left eye. He had recently come from Korea and had suffered frostbite during his time there. It was -30°F on that day. Even though he was wearing all of his Army-issued cold weather clothing, the limited time his face was exposed to the cold, his previous frostbite appeared on his face.
- Medical conditions such as diabetes or other medical concerns that affect blood flow to the extremities.
- Previous frostbite or cold injury
- Being at high altitude, which reduces the oxygen supply to your skin
Hypothermia is the next type of cold weather injury. It is a potentially deadly condition in which the body loses heat faster than it can produce. Prolonged exposure to cold or wet-cold conditions coupled with fatigue, inadequate food intake, and dehydration can lead to a person getting hypothermia. A person can die within a few minutes to a few hours if they develop hypothermia and go untreated. In severe cases of hypothermia in which deep frostbite has formed on the body, medical professionals should treat the individual. Improperly warming a person with an extreme case of hypothermia with frostbite can potentially cause the person to die from shock to the heart due to the circulation of cold blood (Kamler, Surviving the Extremes, 2004, 225-26).
Several risk factors that contribute to enabling the onset of hypothermia are the following:
Cold temperatures along with wet or high relative humidity can foster the development of hypothermia. Wearing damp clothing for an extended period in these conditions will lead to the onset of the loss of body heat. That is why mountain climbers can die wearing mountaineering suits that are heavily insulated. They sweat in them while climbing.
Consequently, they become wet on the inside. The frigid temperatures and wind at higher elevations cause the clothing not to retain the body heat being generated by the climber. The climber cannot remain warm. Hypothermia and frostbite begin to overtake the climber.
Low activity or remaining stationary for too long a period in cold weather can be a cause for developing hypothermia. In the military, standing in a trench or foxhole or sitting in a forward observation/listening post in cold weather can lead to someone getting hypothermia. In World War II, the servicemembers that fought at the Battle of the Bulge were caught by surprise, and many died from hypothermia or froze to death because of sitting in fighting positions in frigid temperatures with minimal clothing to keep warm. A similar experience occurred for the United States Marines who fought at the Battle of the Chosin Reservoir in the Korean War.
Physical fatigue coupled with dehydration and inadequate food intake can contribute to the onset of hypothermia in cold weather conditions. This is why in the movie, Everest, based on the 1996 Everest Disaster, many of the climbers wanted to stop and rest after struggling to descend the mountain to safety in the middle of extreme weather conditions. They were exhausted, frightened and getting cold by their losing the ability to generate body heat at that altitude as well as being encased in their sweat-drenched mountaineering suits. Kamler writes, “Even perfect insulation won’t protect a body that’s not generating heat.” (Kamler, Surviving The Extremes, 2004, 185). Their bodies were wanting to rest from the combined effects of sleep deprivation, physical exhaustion, loss of body heat, and low oxygen at high altitudes. However, in those conditions, stopping to take a break meant almost certain death. Thus, it is important to closely monitor yourself in cold weather conditions to see that you do not over exert yourself to the point of exhaustion whether you are hunting, trapping, mountaineering, backpacking, or camping.
Mental and Emotional disposition in cold weather conditions while enjoying the outdoors is influenced by some of the other factors already discussed. When you are tired, wet, cold, and hungry, your positive mental attitude (PMA) will diminish relative to the time that you are in those conditions. Therefore, it is critical to get dry and warmed up as soon as possible.
3. Immersion/Trench Foot
The third kind of cold weather injury is immersion or trench foot. This type of injury affects the feet due to them being continuously wet in cold conditions (“Trench Foot or Immersion Foot,” CDC, 2014). Some of the medical literature calls it immersion syndrome (FM 4-25.11, 5-8). It is considered a non-freezing injury. Those who suffer from immersion foot in the wilderness can develop frostbite due to the nature of how the problem arises. Immersion foot will begin to form on a person’s feet if they remain continuously wet over several days in temperatures between 30°-40°F. If a person develops immersion foot in those temperature ranges and the temperature begins to drop, it will not take long before the water on the footwear, socks, and fluids on the exposed skin will start to freeze. For more information on keeping your feet healthy in the field, check out my previous article, 3 Essential Tips To Keep Your Feet Healthy.
The winter months bring some severe risks to the bushcrafter, hunter, backpacker, or even those working around the outside of their homes in frigid conditions. A person can have an enjoyable experience outdoors if they remember the medical threats that come with winter outdoor activities: frostbite, hypothermia, and immersion foot. A medical professional can better instruct on how to prevent and treat these injuries. A basic wilderness first aid class will also help you to understand better, prevent, and deal with these injuries.