Frostbite is essentially your body tissue freezing – and it can happen faster than many think.
It was roughly minus 10 degrees with a windchill in the negative 20s in the Twin Cities when adults were off to work and children were waiting at the bus stop Monday morning.
With those subzero temperatures, frostbite is possible in as little as 30 minutes, if not dressed properly, a chart by the National Weather Service shows. The wind chill was nearly minus 50 in International Falls Monday morning – frostbite can happen in about 10 minutes when it's that cold.
Severe cases of frostbite can result in hospitalization, permanent tissue damage or even amputation, the Mayo Clinic says.
Last year, a record number of 200 people had to be hospitalized for frostbite treatment at Hennepin County Medical Center's Burn Center, according to the hospital's blog. On average, the hospital treats about 25 people for frostbite that requires hospitalization.
How frostbite happens
The human body is designed to protect the parts – heart, brain, internal organs – that are crucial for survival, HCMC says.
So, when your body senses cold, it works to make sure an adequate blood supply gets to those important parts, sending less blood to the less-essential body parts – your fingers, toes, feet, hands, nose and ears.
"They’re more likely to freeze up quickly – literally forming ice crystals inside the tissues – and cause blood flow to cease," Dr. Ryan Fey, burn surgeon and critical care specialist at HCMC, said on the blog.
If not dressed correctly, you're at greater risk for frostbite. And consequently, greater risk for nerve damage, infection and amputation.
First your skin becomes very cold and red. That's first degree frostbite (or, frostnip), which usually can be treated with at-home first aid, and doesn't typically cause any permanent damage.
Doctors urge people to seek medical attention if their symptoms are any worse – or get worse – so they can repair the tissue before there is any permanent damage.
Second degree frostbite (or, superficial frostbite) can result in some tissue and nerve damage, and occurs when reddened skin turns white or very pale. When the skin is rewarmed, it may appear mottled, blue or purple. It may also sting, burn and swell, and blisters may form.
Third degree frostbite or severe (deep) frostbite affects all layers of the skin, and people may experience numbness, pain or discomfort. Blisters may also form and the area can turn black and hard as the tissue dies.
When experiencing frostbite symptoms, it's important to get inside and get warm as soon as possible. The Centers for Disease Control and Prevention details more here.
“Rewarming should be done as quickly as possible in a 40 degree water bath. You want to rapidly and definitively rewarm the extremity once – and only once – to avoid the freeze/thaw cycling which magnifies the degree of injury,” Fey explained.
The Mayo Clinic also lists other treatments for severe cases of frostbite.