Winter is upon us, and it’s a good time for reminders about frostbite prevention.

Frostbite is an injury caused by freezing of the skin and underlying tissues, according to the Mayo Clinic. Signs and symptoms include:

  • At first, cold skin and a prickling feeling
  • Numbness
  • Red, white, bluish-white or grayish-yellow skin
  • Hard or waxy-looking skin
  • Clumsiness due to joint and muscle stiffness
  • Blistering after rewarming, in severe cases

Frostbite is most common on the fingers, toes, nose, ears, cheeks and chin. Exposed skin in cold, windy weather is most vulnerable, but frostbite can occur on skin covered by gloves or other clothing.

Parts of the country have already experienced sub-zero temperatures or wind chills. The risk for frostbite increases in temperatures below 5 degrees. In wind chill of -16.6 degrees frostbite can occur on exposed skin in less than 30 minutes. It can also be brought on by wearing clothing that’s not suitable for conditions—for example, clothing that doesn’t protect against cold, wind or wet weather, or clothing that’s too tight.

Smokers, diabetics, those with small blood vessels, young children and the elderly are more susceptible to frostbite.

“Don’t take cold temperatures lightly this time of year. Over-exposure could lead to permanent frostbite damage,” said Tracey Joyner, Clinic Manager at Zip Clinic Urgent Care—Peak Urgent Care in Belgrade, Montana. The number of frostbite cases in the U.S. each year is not tracked but estimated in the thousands. About 1,300 people in the U.S. die from exposure to the cold, according to the Centers for Disease Control and Prevention.

You can treat very mild frostbite with first-aid measures, including rewarming your skin. All other frostbite requires medical attention because it can damage skin, tissues, muscle and bones. Possible complications of severe frostbite include infection and nerve damage.

(Note: Get emergency help if hypothermia is suspected, which could include symptoms such as intense shivering, slurred speech, drowsiness or loss of coordination.)

While waiting for medical attention for suspected frostbite, protect that affected area from further cold, do not walk if feet are suffering, reduce pain with ibuprofen, and do not break blisters that may develop.

Finally, when heading to the urgent care center, be prepared to answer the following questions:

  • List signs and symptoms, and how long you’ve experiencing them to help the doctor get a full picture of your cold exposure and to know if your signs and symptoms have changed or progressed.
  • List key medical information, any other conditions with which you’ve been diagnosed, and all medications you’re taking
  • Note the date of your last tetanus shot.Frostbite increases risk of tetanus. If you haven’t been vaccinated or if your last shot was more than 10 years ago, your doctor may recommend that you be vaccinated.