As the temperatures fall and you start thinking of spending extended periods of time in the cold, you may be worried about Jack Frost nipping at your toes. Obviously, the best thing to do would be to prevent frostbite from happening.
What is Frostbite?
Frostbite is the destruction of tissue caused by below freezing temperatures. When the skin is exposed to the cold, the blood vessels in the skin decrease in diameter, in order to reduce heat loss and keep the core body temperature where it needs to be. With continued cold exposure, the blood vessel walls change, shunting of blood occurs, and finally areas of tissue are bypassed and devitalized.
Frostbite can be divided into four categories based on the severity of damage and symptoms that occur. See the chart below.
We’ve probably all experience the 1st degree frostbite or frostnip. Scraping the windshield without gloves in 15oF weather does it. Simply warming the area by blowing warm air over the surface or placing a warm hand on the area suffices. If treatment occurs quickly, no long-term treatment is necessary.
If the part is truly frozen, and you are still exposed to the cold, wait to treat the area because freeze-thaw-refreeze cycles can cause more damage than leaving it frozen.
If a 2nd-4th degree frostbite is suspected and there is opening of the skin, seek medical attention. Bed rest, elevation and protection of the extremity are necessary. Surgery and amputation may result if the tissue dies as in stage 4, but this may take months to occur. The tissue needs to clearly show where it is damaged, which may takes months.
|Cartoon depiction||Example of clinical picture||Symptoms and description||Treatment and prognosis|
|1st degree: “frostnip||[i]||Superficial freezing of the tips of the digits.Redness, itching, mild swelling. From 3 hours after thawing up to 10 days||Rewarm the area. No permanent damage or tissue changes.|
|2nd degree: superficial frostbite||[ii]||[iii]||Superficial and subcutaneous freezing. Deeper structures are spare.Blisters 24-48 hours. Over the next few weeks, old skin will slough off, leaving red, new skin||Rewarm the area.Long term cold sensitivity can result.|
|3rd degree: deep frostbite||[iv]||[v]||Skin and subcutaneous freezing with tissue loss and ulceration. Blood filled blisters arise. Hard black scabs appear and fall off over several weeks leaving a beefy red skin beneath.||Healing time takes on average 68 days. Hyperhidrosis or increased sweating starts around 4-6 weeks and may last for months|
|4th degree: deep frostbite||[vi]||[vii]||Complete death and loss of deep tissue and bone. Areas with this damage are solid to the touch. Severe pain upon thawing||When rewarmed, skin is a red/purple with loss of sensation. Area quickly turns black, dry and hard 3 days 3 weeks after it thaws.Cold sensitivity, loss of sensation, numbness and pain may result.|