Planning to attend the St. Paul’s Red Bull Crashed ice races, a Special Olympics Polar Plunge, or a winter festival activity? Information is available about how to prevent frostnip and frostbite, but it’s worth learning how cold temperatures affect the skin. Individuals with disabilities who want to enjoy outdoor fun need basic information about the abnormal physiological effects of cold weather exposure.
The skin is the body’s organ of protection for interface with the environment. Among its many functions, the skin is involved in the regulation of temperature. When the body is unable to compensate for cold exposure, there may be tissue injury.
Impaired local circulation is the primary contributor to frostbite. Anyone whose circulation is already impaired at room temperature will be at risk for frostbite sooner with exposure than a person with normal circulation. Thermoregulation is a complex physiological process within the body. The abnormal things that occur in the body with the development of frostbite occur in phases. The first is the prefreeze phase. This is when tissue temperature ranges from 37 ° to 50 ° F. Secondary to chilling and prior to ice crystal formation, superficial sensation is generally lost at 50 ° F.
The second, freeze-thaw phase is caused by ice crystal formation within the tissue. The third, vascular stasis phase involves abnormal changes in blood vessels, such as spasticity, dilation, plasma leakage, stasis blood clotting and circulation shunting. The fourth, the late ischemic phase (cell injury, followed by tissue death).
Overlap occurs among these phases, and the changes during each phase vary with the rapidity of freezing and duration and extent of injury. Tissue cells can be affected by freezing in three different ways. Some skin cells may be unaffected, but others can be killed. In the third situation, a large number are injured but may recover and survive under the right circumstances.
The book Wilderness Medicine Management of Wilderness and Environmental Emergencies by P.S. Auerbach provides an excellent overview of how frostbite affects human skin and underlying tissue, and how cells are affected.
For more information regarding prevention and early management of frostbite, visit www.webmd.com/ skin-problems-and-treatments/features/frostbite-treatment-prevention-faq-feature
The Red Bull Crashed Ice course is probably not accessible this year so stay off the course, stay warm at the sidelines and have a great time!
Wolfe is a physiatrist or rehabilitation physician. Rehabilitation physicians are medical doctors who have completed training in the medical specialty of physical medicine and rehabilitation. She is licensed to practice medicine and surgery in Minnesota. She is a Board Certified Independent Medical Examiner (disability medicine expert).