Winter is here! Anyone out and about in the cold wet weather is at risk for some temperature related injury if they do not follow some basic common sense precautions. Understanding how hypothermia happens and what things make you at risk can help prevent mild and severe cold related problems.
The biggest risk is the actual temperature and the length of time of exposure to the cold. Wet clothing and wind can greatly enhance the dangerous effects of the cold temperatures. The metabolism of your own body is your only source of heat. Fortunately it is very good at producing heat and regulating body temperature with an elegant thermostat mechanism. Your body temperature is the balance between the ability to produce heat and actual heat loss. The brain initiates sweating to cool your body, while inducing shivering and increased hormone production to maintain adequate heat in response to external cold temperatures.
Hypothermia and frostbite can be very mild or very severe. In its mildest form the heart rate increases as well as faster breathing. When you are too cold, shivering and other involuntary movements to stay warm start happening without even thinking about it. Poor coordination and not thinking clearly are common which can impact your immediate safety and outcome. If the hypothermia progresses the senses and mental status are even more dulled and even the shivering or willingness to move diminish. Serious heart, lung and other vital organ complications ensue due to decreased blood flow. Children are more prone to hypothermia due to their small size and smaller reserves for heat production and energy storage compared to adults. Young infants do not have the ability to shiver and being unable to express themselves are more vulnerable to prolonged cold temperatures without any obvious warning signs. Elderly adults may also have less capacity or resistance to cold temperatures being unable to respond quickly to environmental changes, decreased metabolic reserves, chronic illness, or some medications. It is well known that certain medications such as antidepressants, narcotics, general anesthesia, some blood pressure meds, and alcohol consumption all impair the ability of the body to regulate temperature.
True frostbite is when exposed tissues actually freeze and form ice crystals in the cells of the respective tissue. This leads to severe tissue damage and even death. However most of us will only encounter mild forms of this process which start with swelling, pallor, blanching and numbness of the skin. Hands feet and face are the most common areas involved because of their exposure and most peripheral parts of the body farthest from the heart and warmer core temperatures. Blisters that are clear or blood-filled, discoloration of the skin, surrounding swelling and redness indicate more advanced problems. Getting to medical care is paramount if clues suggest serious complications.
Exposure to extreme cold for prolonged periods of time is an obvious challenge to be avoided. Windy conditions make it more difficult to maintain the heat produced by your body as can wet clothing. The moisture accelerates the heat loss dramatically. With prolonged exposure, wet conditions, and wind coupled with inadequate preparation, temperatures do not have to be freezing to create critical problems. 50 degree weather can be problematic with some wet clothes and wind. Frostbite occurs in the workplace in industries using cold storage of common refrigerated and frozen food products. Overzealous use of an ice pack on an injured knee or sprained ankle can cause accidental frostbite if over used especially when in direct contact with the skin without some dry cloth to mediate the effect on bare skin. Ice packs should be applied intermittently for only a few minutes at a time.
Re-warming the body part or individual is the most important treatment for the consequences of cold exposure. It is important to avoid re-freezing if this is a risk. In fact re-warming a truly frozen part should be delayed until you reach some place where re-freezing is no longer a risk. Warm dry clothes and blankets do wonders to eliminate the continued loss of heat. Remember we are typically trapping and conserving our own body’s heat. If possible get to a warm dry location. Any external heat source could be of benefit. Placing cold hands or feet in warm, not very hot, water can be helpful. Putting cold hands in the arm pits or groin area to facilitate warming provide some initial relief. In extreme situations body to body contact with warm dry blankets can help the person suffering from hypothermia in a remote location.
Prevention is being prepared which need not be expensive. Proper clothing and supplies are important whether it is a trip downtown, day hike, or wilderness trip. Plan for the unexpected. Weather conditions in remote areas can change abruptly in the fall or winter. Bring some options with you. The best way to avoid cold related injury is to dress in layers that can be removed as conditions dictate. Limit the time in the cold as much as possible. Stay dry! Waterproof footwear and suitable covering for head and hands is a must. Drugs, alcohol and tobacco can seriously impair your judgment and the ability to tolerate prolonged exposure to the cold. Stay well hydrated and bring a few extra supplies whether planning a day trip or expedition. A small amount of planning and just a bit of that “expedition mentality” can help avoid problems and keep you a lot more comfortable when out in the cold weather.