You’ve probably heard that the cells in your body are 70% water. But what happens when it gets so cold that all that water inside your cells starts turning into ice crystals?
Here’s the short answer: The ice in your cells causes them to burst. Damage to your blood vessels causes the vessels to clot. New blood can’t get through, and the tissue on the other side of the clot dies. And that is what frostbite is.
“The decreased blood flow basically prevents that tissue from having any chance of recovering,” said Dr. Cameron Gibson, a surgeon at UCHealth University of Colorado Hospital who specializes in treating burns and frostbite.
So, hey, let’s not allow that to happen. Here’s some tips from Gibson and Dr. Arek Wiktor, the medical director of UCHealth’s Burn & Frostbite Center, on how to avoid frostbite and how to identify if those numb fingers and toes require medical attention. The center sees between 30 and 60 patients a year with frostbite injuries and consults on another 90 to 100 additional cases seen at other hospitals.
Cold + wind = bad news
The body loses heat primarily through what Gibson called convective heat loss. That’s basically when your body heat escapes into the air. The heat loss is made worse when there is wind blowing to whisk more heat away from your body.
When wind chills drop down to minus 50 degrees or colder, frostbite can develop in a matter of just a few minutes, even for healthy, active people.
In fact, Gibson said a person’s activity level could provide a kind of false comfort. If you’re out shoveling snow or working outside, you might not feel that cold. But it’s a trap. Gibson said he’s treated plenty of patients who suffered frostbite even though they were being active while outside.
“Their core body temperature is maintained because they’re producing heat by working out,” he said, “but that doesn’t necessarily help by producing heat in the fingers and toes.”
Extremities like fingers and toes are most at risk because that is where the body first pulls back blood flow during cold weather — a phenomenon called “vasoconstriction.” But any patch of exposed or under-insulated skin can suffer frostbite.
Be especially sure to watch out for wet gloves or socks. Water compounds the heat loss, creating an even greater risk for frostbite.
Cold + alcohol = even worse news
Drinking alcohol may make you feel warm, but, again, it’s a trap. The feeling of warmth that alcohol creates is the result of what Gibson called “unregulated vasodilation.” In other words, your blood vessels relax and blood flows in, giving you a reddish flush.
But all that blood near the surface of the skin leads to increased heat loss.
“You’re losing heat everywhere, so drinking alcohol is not good,” he said.
Alcohol — or other intoxicating drugs — can also make you less aware of how cold you’re getting. Wiktor, in a video recorded by UCHealth, said drug or alcohol use is a common co-occurrence in many frostbite patients.
Don’t try to tough out numb
If your toes and fingers are numb, go inside. Don’t be a hero.
Gibson said the key to avoiding frostbite if you must be outside is to take frequent warming breaks. Numbness isn’t normal and it isn’t a badge of toughness. It won’t go away on its own.
“The worst thing to do is to tough it out and 45 minutes later you still can’t feel your fingers or your toes and now it’s frostbite,” Gibson said.
He recommends fully rewarming fingers and toes and making sure they look all right — the goal is a nice, healthy pink color — before heading back out.
For people with darker skin tones, it can be harder to spot warning signs just based on color changes. But skin that is stiff, tingly, painful or lighter in color than your natural skin tone are all possible warning signs.
What to do when your fingers are turning colors
So, let’s say your fingers or toes aren’t looking good when you come inside. It’s time to take action.
Gibson and Wiktor recommend immediately rewarming them in warm water — not hot because, even if you can’t feel it with your numb digits, hot water can still burn you. Gibson said people should try to have a buddy who can make sure the water isn’t too warm. Absent that, Wiktor recommended water at a temperature of 100 degree Fahrenheit.
Soak and wait. Both said the rewarming should last 30 minutes.
If after that the affected area is still a funky color — dark red, purple, blue, gray — or is blistered, it’s time to get medical help.
Don’t wait to go to the hospital
This part is key: Do not wait to go to the hospital. If you do, they might not be able to help you as well.
The hospital will likely put you on blood thinners to help beat those clots that are killing your tissue. But the blood thinners aren’t effective more than 24 hours after the injury.
“A lot of people, the injury will happen and they will ignore it or for whatever reason they won’t make it to the ER until two or three days later,” Gibson said.
And when that happens there’s not much doctors can do. Remember that Gibson, who treats a lot of frostbite injuries, is a surgeon. Amputation is a common outcome for people who don’t seek help fast enough.
“The vast majority of frostbite injuries are preventable,” Wiktor said. “So it’s honestly sad when I see these types of patients come in with these types of injuries, people who will have life-altering amputations. Some people lose all of their fingers just because of a mistake.”