Tuesday, May 10, 2011

This (frost)bites

I did a good one on myself a while back. It was the Boy Scouts' District Camporee and I'd just woken up and, by definition, required coffee. I got out the propane stove and began setting it up. Unfortunately, I didn't realize the propane hose was pressurized and it let out a blast of propane from the fitting. Now, the day was going to warm up but mornings are still cool here in the desert. And, actually, the depressurizing jet of gas alone was cold enough to cause frostbite. So that's what it did; right across the back of my right index finger. What did I do? Grabbed it with my left hand to finish tightening down the fitting. And now I had frostbite across the back of my left index finger, too.

Warning, the following section includes graphic pictures of injury.

Frostbite is simply the formation of ice crystals within cells. It can only occur in below-freezing temperatures although those freezing temperatures can be highly localized, as in my case. Frostbite mainly affects the extremities and exposed skin like hands, faces, and feet. This is a thermal injury and, with minor variation, will resemble and be treated like a burn.
This bites.
Superficial frostbite will leave the skin white, gray-yellow, or waxy. The injury is cold and numb but may also tingle or ache. While the skin surface will feel stiff, the underlying tissue will still be soft.
Fortunately, the day was going to be warm and I was able to begin treatment immediately.
Deep frostbite will turn the skin pale and possibly waxy. The affected area will be cold and solid, like something from the frozen meat case at the grocery store. The injury, which started painfully cold, will stop hurting as the nerve endings freeze and die. So there's that. When the area is rewarmed, blisters may appear, resembling a second-degree burn.
The astute reader will notice that both pictures above show blistered skin. The day of the injury, both sites were charcoal-gray surrounded by inflamed red and the skin blistered after about an hour.
Getting treated.
Frostbite is treated the same way, regardless of severity. First, get the victim to a warm area and remove any wet clothing and anything that may constrict blood flow like a ring. Superficial frostbite will often heal on it's own when treated as a burn. Deep frostbite victims should be evacuated to a medical facility; the cold blood going back to the heart can trigger a heart attack.
In the olden days, the treatment of frostbite was quite barbaric. The affected limb would simply be amputated with no attempt to save it. Nowadays we know that even cases of deep frostbite, when thawed safely, can see full recovery.
Not as bad as it looks.
Do not rub or massage a frostbite injury; the formed ice crystals will just compound the damage. Like any blistering injury, avoid breaking the blisters. If blisters do break, treat as usual with a topical antibiotic and liquid bandage. And like any major injury, don't allow the victim to smoke or drink alcohol. Don't rewarm the injury with a stove, fire, or vehicle exhaust. Do not apply ice, snow, or cold water. Finally, don't rewarm the injury if there is any possibility of refreezing and, obviously, don't let the frostbitten area refreeze.
I know of one case where a man had deep frostbite on his foot. This individual was hunting in the backcountry with a group. Because of the high chance of refreezing before he could reach definitive medical care, he left the foot frozen. He put on a wet sock and was driven to the hospital with his foot sticking out the passenger window. The doctors were able to recover his entire foot.
Like new.
After the frostbite is safely thawed, it's treated just like a second-degree burn. Use dry sterile gauze between the fingers and toes to prevent them sticking as they thaw. Elevate the injury to reduce pain and swelling. Aspirin or ibuprofen are allowed for pain and inflammation; don't administer to children. Apply aloe vera to treat the burn and liquid bandage to reinforce the blisters. Seek medical care. Fortunately, I'm certified to treat just such an injury.
All pictures copyright of the author, released under Creative Commons, Attribution, Share-Alike license terms.