It can happen easier than you can imagine. You head outside on a cold winter day with the kids to do some sledding. It’s 20 degrees (not unusual this winter here in Pennsylvania). You throw on a pair of white athletic socks and an old pair of snow boots. They’re thin, but they’ll be okay.
After only one hour you notice that you can’t, at least you think you can’t, feel your toes on your right foot. Not like they’re no longer attached to your foot, they are – it’s just that you have no sensation of them being there. Hmm.. Weird. Never felt that before. You stomp your feet to warm them up a bit, get the circulation going again, you walk around to keep the muscles flexing. But the numbness gets worse. And they itch like mad. But back on the sled you go, because you’re having fun.
After another hour, you get home and take off your shoes and socks. The skin on your feet and toes feels like ice when you touch it. But your toes don’t register as being touched. That is, you see your fingers touching your toes, and your fingers feel like they’re touching something icy, but that’s it. No feeling of being touched from the opposite direction.
After 15 minutes, as the skin begins to warm, the throbbing begins. It gets more intense until it becomes excruciatingly painful. The throb is like someone hammering on your toes. You wrap your feet in a wool blanket, and after two hours, the pain and throbbing subside.
Those symptoms are consistent with a condition called frostnip, in which blood retreats from the tissues, but no significant long-term tissue damage occurs. Yet there’s a very, very thin line between frostnip and frostbite, in which toes and feet become so damaged, they sometimes have to be amputated.
How frostbite occurs
When the temperature drops below freezing, the body’s natural response is to move the blood vessels away from the skin to preserve core body temperature. When your feet or toes are exposed to these conditions for hours or days, blood flow becomes very restricted in the exposed areas and the tissue begins to die.
There are four degrees of frostbite:
This is frostnip, as described above. Frostnip only affects the skin, which becomes frozen. It begins with itching and pain, and the skin develops patches of yellow, white, or red, and eventually becomes numb. Long-term damage is minor, and may include insensitivity to heat and cold.
A little more serious, the skin becomes frozen and hard, but the deep tissue remains normal. Within two days, the injured area usually forms blisters which appear hard and black. Healing takes about one month, but insensitivity to heat and cold is usually permanent.
Third and Fourth Degree
This is when the deep tissue also becomes affected by freezing temperatures. Muscles, tendons, and blood vessels freeze. The skin becomes hard and waxy and the toes or foot become difficult or impossible to move. Black or purple blisters form, which are filled with blood, accompanied by a loss of sensation, which is sometimes permanent. In some cases, the frostbitten areas become gangrenous, which requires amputation to stop the infection from spreading throughout the body.
How to treat a frostnip or frostbtten toe or foot
If you believe you have frostbite or frostnip, never rub the area to restore circulation, because you’ll damage it further. The tissue is frozen and full of ice crystals, and these crystals can cause significantly more damage. Your toes or feet will feel intensely cold, like blocks of ice, but don’t rub them. If you’re indoors and the room is warm, take off your shoes and socks, and let your feet and toes warm naturally.
If you’re not in a warm area, wrap the foot in a blanket or something else that will trap as much natural body heat as possible to help warm the foot. However, if there’s a chance that the foot may freeze again, do not rewarm it. Do not walk on the injured foot, as it may cause further damage.
In a hospital environment, active rewarming is usually employed. This involves applying heat to the area in a controlled way to thaw the tissue faster. The faster the tissue regains blood flow, the less permanent or long-term damage will occur. Active rewarming is usually achieved by soaking the damaged foot in a warm water bath of roughly 100 degrees (F). If you’re not in a hospital setting, it’s okay to use the warm water bath yourself, but make sure that the temperature is not over 100 degrees or you may scald your foot. Never use a heat source such as a heating pad, stove, or cooking fire.
Long term consequences of frostbite may include permanent changes in sensation, a feeling of tickling or tingling in the damaged area for no apparent reason, increased sweating, and arthritis in the affected area.
If you’ve suffered frostbite of your feet or toes, please seek medical attention from a podiatrist immediately – it’s not to be taken lightly.