Primary Care in Rochester and Kasson

Frostnip or bite, cold weather can hurt

1/6/2022 by Matthew Bernard, M.D.


Like it or not, it's that time of year when the temperature drops. While it may be tempting to just hibernate over the winter, it's important to stay active for your overall health. 

But when you are out in cold weather, you run the risk of injury from the cold. 

Cold injuries are caused by prolonged exposure to low temperatures. They may or may not involve actual freezing of body tissues. The young and elderly are especially prone to these injuries. And drinking alcohol increases your risk. 

Two common cold-weather injuries are: 

  • Frostnip, or chilblain 
    While this injury is painful, there is little or no permanent damage. Frostnip is the stage before frostbite begins. It appears as red, swollen skin that's tender and hot to the touch. Your skin also may itch. These symptoms can worsen to an aching, prickling "pins and needles" sensation that is followed by numbness. Frostnip can develop in only a few hours if your skin is exposed to extreme cold. 
  • Frostbite 
    This injury is much more serious and can cause long-term harm. It typically affects areas of your body, such as fingertips, earlobes, cheeks, chin and the tip of your nose. If an area of the body reaches 23 degrees Fahrenheit and that area stays that cold for an extended period, ice crystals form in the tissues. In other words, these tissues start to freeze. 

There are four degrees of frostbite, and it may take three to four days to determine the degree: 

  • First and second degree 
    Signs and symptoms include blanching, where the skin turns white; temporary numbness; redness; and stinging and burning as the skin is warmed. 
  • Third and fourth degree
    These symptoms include swelling, blue-gray discoloration, deep burning pain as the area is warmed, blisters, and gangrenous scab formation within two weeks of injury. 

How to treat cold-weather injuries

To treat cold-weather injuries, you should:

  • Get out of the cold. 
  • Remove any wet or tight clothing. 
  • Gently wash and dry the injured area. 
  • Elevate injured hands or feet.
  • Slowly rewarm the injured areas in warm water (105-110 degrees Fahrenheit) for 20 to 30 minutes or until the skin flushes or turns pink. 
  • Cover injured areas with layers of loose, warm clothes or cloths. 
  • Protect the injured area if there's risk of it freezing again. 
  • If you suspect frostbite, head to an urgent care facility or emergency department. 

How to prevent cold-weather injuries

  • Plan to enjoy winter outdoor exercises and activities, and also plan to minimize cold-weather injuries. 
  • Dress in layers to minimize the amount of exposed skin. Look for clothing that wicks dampness away from your skin and protects you from the wind. 
  • Heed windchill warnings, and head inside if you start to develop symptoms of frostnip. 

Whatever the weather is this winter, stay active, stay healthy, stay warm and stay safe. 

Matthew Bernard, M.D., is a physician in Primary Care in Rochester and Kasson's Department of Family Medicine. He practices at Mayo Family Clinic Northwest in Rochester, Minnesota.