Tow truck personnel work to remove an overturned semi in the median of Interstate 90 at mile marker 218 near the U.S. Highway 52 exit Monday, Jan. 28, 2019, southeast of Rochester, Minn. According to Sgt. Troy Christianson, with the Minnesota State Patrol, the semi was eastbound and went straight off the gradual curve into the median because of blowing snow. Sgt. Christianson said there were no injuries in the crash. (Joe Ahlquist/The Rochester Post-Bulletin via AP)
Record-breaking cold impacting parts of US
02:16 - Source: CNN
CNN  — 

It’s COLD. We’re talking dangerous cold. Cold that might rob you of the tips of your nose, ears, chin, fingers or toes if you’re not careful. Called frostbite, it happens when the skin and tissue under it freezes, which can happen much more quickly than you might imagine.

Cold and wind chill

Frostbite is not only dependent on the outside temperature; it’s also affected by the wind chill factor. As the speed of the wind increases, our bodies cool at a faster rate, causing the skin temperature to drop. Higher altitudes can also affect the speed at which skin can freeze.

Wind Chill Index

The National Weather Service has created a wind chill chart that shows the time it might take to develop frostbite at varying temperatures and wind speed. The index was tested on human face models.

For example, if it was zero degrees Fahrenheit and calm, your chance of frostbite is relatively low. Add wind at 15 miles per hour, and it would take only 30 minutes before frostbite sets in. If the wind rose over 50 mph, it would take a mere 10 minutes for frost to bite.

Your skin would freeze in a scant five minutes if you were out in minus 25 degree weather with a wind speed of just over 25 mph.

Who is at risk?

You are more susceptible to frostbite if you smoke, take medications called beta-blockers, have poor blood supply to the legs, or have diabetes or Raynaud syndrome, a condition in which strong emotions or cold temperatures cause blood vessels to spasm and block blood flow to extremities.

Older people and the homeless without proper clothing, heating and food are also at high risk, as are hikers and hunters who aren’t properly clothed and stay outdoors too long. The US Centers for Disease Control and Prevention also warns that anyone who drinks excess alcohol or uses illicit drugs is at high risk; while you may feel like your body is warmer, your core temperature and blood pressure actually drop.

And of course you are more likely to get frostbite if you aren’t dressed properly for the weather. The CDC has a visual chart that shows the critical areas to keep covered in extreme cold.

The stages of frostbite

The first stage of frostbite is often called “frostnip” and begins with redness and a pins-and-needles feeling. Get out of the cold quickly at this time to avoid further damage to the skin.

Moving beyond frostnip to the more dangerous stages can happen quickly.

A mild nip could be warmed up with your own body heat; try sticking those fingers into your armpit, for example. Rewarm those red toes with a soak in warm – never hot – water for up to 30 minutes. Since you won’t be able to tell with those zapped toes, test the water with another part of the body to be sure it’s comfortable. Rewarm ears, nose and cheeks with warm cloths; re-soak and reapply repeatedly.

Be prepared for a bit of pain as the frostbitten areas come back to life. You’ll know when warming is complete when the skin is soft and all feeling has returned. But don’t use stoves or warming pads, the CDC warns. Those numb bits can’t tell the temperature, and they could easily burn as they warm up.

The second stage of frostbite can appear as white or waxy, with numbness to feeling.

Superficial frostbite is the second stage. It’s known as second-degree frostbite and begins when your skin begins to turn pale white or grayish-yellow instead of red. It might even begin to appear blue. Crystals of ice are beginning to form in the skin, and it may become hard and numb to sensation. Some people say it feels “waxy.”

Because the pain and redness are subsiding, unfortunately, people often don’t realize what is happening to them. But soon, the skin might warm and begin to