When it comes to winter, it is important to be able to promptly identify and if possible, mitigate the risk of a cold weather injury. Cold weather injuries will happen, whether it be you or your partner, or an unprepared homeless man on the streets. This article will cover the identification and treatment of cold weather injuries.
As stated in the previous Cold Weather Awareness article, hypothermia occurs when the body loses heat through a cooler medium either through conduction, convection, radiation and evaporation.
Hypothermia is categorized into three general stages, each dictated by the temperature of the body.
Stage 1 – Stage 1 hypothermia occurs when the body falls between the average 98.6 F, but stays above 95.0 F. During this stage, the body tries to compensate by shivering (creating heat). Due to vasoconstriction and reduced circulation to the extremities, fine motor movements become difficult. The respiratory rate will increase and become shallow and the casualty may feel lethargic.
Stage 2- Stage 2 hypothermia is when the body has fallen below 95.0 F but is still above 90 F. The casualty may start to become confused but can still think semi-coherently. The casualty may start shivering violently and fine motor movement is virtually non-existent. The body constricts all the vessels on the surface even further, making the casualty look pale. The lips, toes and fingers might have a bluish color as well due to lack of circulation.
Stage 3- Stage 3 hypothermia occurs when the body temperature drops below 90 F. The body will have exhausted itself shivering so the casualty may be very still. Speaking may be very difficult and the casualty will be incoherent. Irrational decision making may occur and the casualty will lose gross motor skill in the hands. The casualty may be unable to walk, and will also appear very lethargic. The skin becomes blue and may start to swell. Respirations and heart rate decrease and the casualty may go unconscious (Fiji, 2009).
Treatment for Hypothermia
The first priority of treating for hypothermia is to remove the casualty from the cold environment. Wet clothing will greatly reduce body temperature so it should be removed immediately. Replace the wet clothing with layers of dry clothing and shield the casualty from the wind, and place something between them and the cold ground. Maintain the casualty supine, and if they are in severe hypothermia, do not give anything to eat or drink.
Active rewarming- Place the casualty in a casualty blanket or inside a sleeping bag. If evacuation times are prolonged, you can place another person inside the sleeping bag stripped down to their underwear to share the body heat (McInerney, 2002).
Risk of cardiac dysrhythmia- If the casualty is unconscious, handle him/her very gently as sudden movements may cause ventricular fibrillation. Have an AED or defibrillator on standby if possible (Journal of Special Operations Medicine).
Fluids- If qualified, administer IV fluids containing glucose warmed to 101.6 F or 1 amp of D50. The glucose will help fuel the body after it has depleted energy shivering.
Paradoxical undressing- When a body reaches a deadly hypothermic temperature, the vessels may become fatigued and dilate throughout the body. This can cause an extreme heating sensation in a casualty already showing signs of an altered mental status. This can cause a phenomenon called “paradoxical undressing”. A less severe version of this is seen with people consuming alcohol. The alcohol causes dilation of vessels, which in turn causes the person to remove layers of clothing. An altered mental status, due to either alcohol or severe hypothermia, combined with widespread vessel dilation, can cause a very poor outcome if the casualty decides to undress (Wedin, 1979).
Freezing Cold Injuries
Freezing cold injuries are those that occur to exposed skin and usually fingers and toes. It is important to keep all exposed skin covered to avoid this, especially from the wind.
Frostnip- The first stage of frostbite is frostnip. This occurs when exposed skin becomes very cold and irritated. The skin may turn very red and feel cold to the touch. As the cold progresses, it may feel numb and tingly. Rewarming will usually cause a stinging and burning sensation. To treat frostnip you must first cover the exposed skin. Using a warm hand directly over the area could be enough to rewarm the affected skin. If in the lower extremities, elevate the feet and change socks. NSAIDS (Non steroidal anti-inflammatory drugs) may help as well.
Frostbite- As ice crystals begin to form in your skin, the skin may become white or very pale. When there is serious skin involvement, the area may feel warm. To rewarm this area immerse it in warm water (104-107F) and cover it with a warm blanket. As the frostbite progresses, it may become severe and damage deep tissues as well. Joints and muscles may cease working and large blisters may form 24-24 hours after rewarming. The tissue may turn very dark and hard, indicating that the injured area has died (Mayo Clinic, 2012).
Treatment guidelines for frostbite are as follows:
Superficial frostbite without chance of refreezing- Use warm water immersion or attempt to warm the extremity in the armpit or groin. If qualified, drain the clear blisters using aseptic techniques. Apply a soft sterile dressing around the injury. Consider pain control per local protocol.
Deep frostbite without chance of refreezing- Warm water immersion for approximately 30 minutes, or until tissue is soft. Apply a loose sterile dressing prior to transport and ensure fingers and toes are separated. Do not train blood blisters. Patient will likely need pain control per local protocol.
If refreezing is likely to occur- Do not attempt to thaw the tissue. Protect the tissue from further injury by wrapping it with a dry sterile dressing. Separate the fingers and toes as well.
Ensure that the casualty does not walk on the injured limbs unless needed for preservation of life. If thawed, refreezing will likely cause amputation of the injured limb. Do not use fire or intense heat to rewarm injured tissue. Do not rub the injured tissue with snow or ice. Massaging the injured limb will likely cause more damage.
It is extremely important to be able to identify and treat these injuries. Being able to assess and prevent an injury like frostbite can save a finger or even a limb. Continue to inform your department on the risks and treatments of cold weather injuries annually.
Wedin, B. (1979). “Paradoxical Undressing” in Fatal Hypothermia. National Institute of Health. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/541627
Mayo Clinic Staff (2012). Symptoms of Frostbite. Mayo Clinic. Retrieved from http://www.mayoclinic.com/health/frostbite/DS01164/DSECTION=symptoms
McInerney, J. (2002). Accidental Hypothermia and Active Rewarming. Emergency Medicine. Retrieved from www.ncbi.nlm.nih.gov/pmc/articles/PMC1725881/
Fiji. (2009). Hypothermia’s Three Fatal Stages. The Fiji Times. Retrieved from http://www.fijitimes.com/story.aspx?id=130806
About Hank V.
Hank is a 6-year veteran currently serving in the U.S. Army Special Operations Forces as a Combat Medic. He has deployed to East Asia and the Middle East.