Frostbite possible even at above-zero temperatures
17.12.2014 11:57:31
How to protect yourself from frostbite?
(P.Ustinov, Maryina Gorka)
(P.Ustinov, Maryina Gorka)
Areas lacking a protective layer of fat are at risk, such as fingers and toes, the nose, aural cavities and face. At low temperatures, the smallest blood vessels constrict, slowing blood flow and stopping tissue enzymes from working properly. First-degree frostbite (mild) usually happens over a short period, making skin pale, but returning to a bright red colour on warming. The skin retains essential blood flow but may peel a little after a week, and full recovery may take 5-7 days. The first signs are a burning sensation, tingling, subsequent numbness and then itching — slight or acute.
Second-degree frostbite arises with longer exposure, with initial blanching, cooling and loss of sensitivity (as observed at all degrees of frostbite) followed by blisters in the first few days. It can take 1-2 weeks to regain full use but there will be no permanent scarring. Even after warming, pains will be intense and take some time to subside, followed by itching and burning sensations.
Third degree frostbite features blisters filled with blood, rather than clear fluid: blue-crimson at the base and lacking all feeling, since the skin has died. If nails are lost, they will not grow again, or will likely be deformed. Skin continues to die for 2-3 weeks and scarring proceeds for up to a month. The intensity and duration of the pain is more acute than in the second degree.
Fourth degree frostbite arises after very long exposure and is often combined with lesser degree frostbite, with all layers of soft tissue, bone and joints affected. Limbs become marbled with blue and warming can bring about swelling. As skin temperature has dropped greatly, the consequences are most severe. Where swelling is worst, there may be an absence of blisters, but a complete and enduring loss of sensitivity. After long periods, the whole body is affected, rather than just the extremities.
Next time, we will talk about first aid for frostbites.
Take care.
By Tatiana Zhukova, doctor of higher category, D.M. Ph.D.