Frost Damage

Chilblain

Your extremities are about to suffer again. Chilblain is an inflammatory swelling to the skin of your feet, hands, face and ears, caused by cold exposure. In contrast to frostbite, the skin does not freeze, but may leave some permanent damage to the fine blood vessels. In instances where the affected areas become sensitive to cold, the symptoms return quickly after every exposure. The skin develops red pimples or patches and may itch, burn or sting. It can worsen to painful swellings and blisters. The preferred treatment is to gradually warm the affected area, as sudden rewarming aggravates the condition.

Frostnip

An untreated chilblain may develop into frostnip. Frostnip freezes the outer layers of fingers, toes, face and ears. Other than exposure to severe cold, contact with cold metal or liquid is often the cause. Poor circulation in the extremities worsens the situation. If treated immediately, the injury is generally reversible. If not, the condition develops further into the dangerous frostbite.

Frostnip is hard to distinguish from frostbite. The frozen layer of the skin appears similarly white and waxy, but feels rubbery. In contrast, frost-bitten flesh is hard as deeper layers are frozen. The nipped skin turns red and sometimes painfully swollen after rewarming. Like sunburn, the affected area sheds a dead layer of skin after a few days of healing. Repeated frostnip injury may lead to cold sensitivity.

As with chilblains, preventing cold exposure by wearing the appropriate clothing is better than a painful cure. If you do have to be in the elements, always check your exposed skin for numbness and look out for a change in colour. Gently warm nipped areas. Do not massage the area because the ice crystals can damage the skin tissue, aggravating the injury.

Frostbite

Skin and flesh freezes at about –2°C. Superficial frostnip heals, but the freezing of deeper layers results in permanent damage. Circulation stops, fine arteries burst, blood clots and cells die. Mechanical damage occurs when the ice crystals puncture cells during rubbing of the area or if the person continues to walk on affected feet. The dead tissue will eventually decompose and, depending on the severity of the damage, the limb may have to be amputated.

Sounds terrible? It is quite fortunate, really. Because that is how the temperature regulator, the hypothalamus, reacts to cold extremes. Its loyalty is towards the essential organs to keep you alive – a hand or foot can be discarded. Frostbite is, therefore, not life-threatening. But it leaves the victim with scars and long-term complications such as persistent pain, joint problems and an increased cold sensitivity.

Over 3,000 male conscripts of the Finnish defence force took part in a study to find the number of incidences and severity of frostbites. The researchers found that almost 2 per 1,000 conscripts developed frostbites annually. The majority of injuries were superficial and common to the ear (58%). Most at risk were those not wearing the appropriate clothing, such as earflaps or scarves. Individual cold sensitivity was a significant factor.

Frostbites are caused by:

• Low temperatures. Temperatures below –2°C can induce frostbites on exposed body parts. The danger increases when low temperatures combine with moisture (wet clothing) and wind chill.
• Supercooled substances. Metal reaches temperatures well below freezing point. Skin and flesh freeze instantly when in contact.
• Tight-fitting garments such as shoes, hats, watchbands and belts restrict the blood flow and increase the likelihood of cold injuries.
• Medication and drugs. Some substances, e.g. nicotine, constrict the blood vessels in the periphery.

Frost_biteFrostbitten skin appears waxy-white and is rigid. An initial tingling sensation and feeling of coldness soon gives way to numbness. Due to the lack of pain, the victim may no longer be aware of the injury. A superficial frostbite contains some life in the tissue and thawing results in swelling and blistering of the area. Frostbites, which involve freezing of the muscles and/or bones, don’t show signs of blistering after rewarming. The exception is the area bordering the frostbite, which has superficial damage where blood-filled blisters may develop.

Prevention is the same as for frostnip. Treating frostbite is a gentle process. The old theory of rubbing the affected area with snow is no longer applicable, as it will further damage the tissue. Obtain emergency medical assistance as quickly as possible.

Trench foot and immersion foot

If only your unhappy potted daisy could talk. Unhappy because it has to grow in a prison pot; and unhappy because the well-meant caring is often overdone by too much watering. The poor daisy is wilting. The roots are rotting.

Soldiers aren’t daisies but their plight may also go unheard by their carers. Hundreds of thousands of Napoleon’s and Hitler’s soldiers walked through mud and slush in their quest to conquer Russia. The adversaries of WWI spent days, weeks and months in soggy French trenches. Like the daisy’s roots, human feet don’t appreciate wet conditions. Add low temperatures and feet will rot – literally.

Trench foot has its name from the disease that debilitated WWI soldiers during trench warfare in wet and cold conditions. In spite of its association with the military, equally at risk are outdoor workers, hunters, hikers and anglers. They often wear tight-fitting and non-breathing rubberized boots over a lengthy period. Immersion foot is similar but, as the name suggests, is associated with continuous immersion of feet in water.

Although trench foot and immersion foot are non-freezing injuries, the symptoms compare with those of frostbite. They are localized and occur mostly, but not exclusively, at the feet. At first, the affected area underneath the soft skin itches, tingles and feels numb. Later, red or blue blisters appear that either weep or bleed. The treatment for trench foot is similar to frostbite.

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