Much of the U.S. is facing severe winter storms and subzero temperatures. And one of the first concerns, if you're outdoors, should be frostbite.

Frostbite is an injury caused by the freezing of the skin and underlying tissues.  Frostbite is most common on the fingers, toes, nose, ears, cheeks and chin. Exposed skin in cold, windy weather is most vulnerable to frostbite. But frostbite can occur on skin covered by gloves or other clothing. You may not realize you have frostbite until someone else points it out.

Here is some information about frostbite from our Mayo Clinic Care Network:

Signs and Symptoms

• 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

Stages

Frostbite occurs in several stages:

• Frostnip. Frostnip is a mild form of frostbite. Continued cold exposure leads to numbness in the affected area. As your skin warms, you may feel pain and tingling. Frostnip doesn't cause permanent skin damage.
• Superficial frostbite. Superficial frostbite causes slight changes in skin color. The skin may begin to feel warm — a sign of serious skin involvement. If you treat frostbite with rewarming at this stage, the surface of the skin may appear mottled. And you may notice stinging, burning and swelling. A fluid-filled blister may appear 12 to 36 hours after rewarming the skin.
• Deep (severe) frostbite. As frostbite progresses, it affects all layers of the skin as well as the tissues that lie below. The skin turns white or blue-gray and you lose all sensation of cold, pain or discomfort in the area. Joints or muscles may stop working. Large blisters form 24 to 48 hours after rewarming. The tissue turns black and hard as it dies.

Prevention

Frostbite can be prevented. Here are tips to help you stay safe and warm.

• Limit time outdoors in cold, wet or windy weather. Pay attention to weather forecasts and wind chill readings. In very cold, windy weather, exposed skin can develop frostbite in a matter of minutes.
• Dress in several layers of loose, warm clothing. Air trapped between the layers of clothing acts as insulation against the cold. Wear windproof and waterproof outer garments to protect against wind, snow and rain. Choose undergarments that wick moisture away from the skin. Change out of wet clothing — particularly gloves, hats and socks — as soon as possible.
• Wear a hat or headband that fully covers the ears. Heavy woolen or windproof materials make the best headwear for cold protection.
• Wear mittens rather than gloves. Mittens provide better protection. Or try a thin pair of glove liners made of a wicking material (such as polypropylene) under a pair of heavier gloves or mittens.
• Wear socks and sock liners that fit well, wick moisture and provide insulation. Consider hand and foot warmers as well. Be sure foot warmers don't make boots too tight, restricting blood flow.
• Watch for signs of frostbite. Early signs of frostbite include changes in skin color, prickling and numbness. Seek warm shelter if you notice signs of frostbite.
• Plan to protect yourself. When traveling in cold weather, carry emergency supplies and warm clothing in case you become stranded. If you'll be in remote territory, tell others your route and expected return date.
• Don't drink alcohol if you plan to be outdoors in cold weather. Alcoholic beverages cause the body to lose heat faster.
• Eat well-balanced meals and stay hydrated. Doing this even before you go out in the cold will help you stay warm.
• Keep moving. Exercise can get the blood flowing and help you stay warm, but don't do it to the point of exhaustion.

Treatment

Mild frostbite (frostnip) can be treated at home with first-aid care. For all other frostbite, after appropriate first aid and assessment for hypothermia, medical treatment may involve rewarming, medications, wound care, surgery and various therapies, depending on the severity of the injury.

• Rewarming of the skin. If the skin hasn't been rewarmed already, your doctor will rewarm the area using a warm-water bath for 15 to 30 minutes. The skin may turn soft. You may be encouraged to gently move the affected area as it rewarms.
• Oral pain medicine. Because the rewarming process can be painful, your doctor will likely give you a drug to ease the pain.
• Protecting the injury. Once the skin thaws, your doctor may loosely wrap the area with sterile sheets, towels or dressings to protect the skin. Or the doctor may protect your fingers or toes as they thaw by gently separating them from each other. And you may need to elevate the affected area to reduce swelling.
• Removal of damaged tissue (debridement). To heal properly, frostbitten skin needs to be free of damaged, dead or infected tissue. To better distinguish between healthy and dead tissue, your doctor may wait 1 to 3 months before removing damaged tissue.
• Whirlpool therapy or physical therapy. Soaking in a whirlpool bath (hydrotherapy) can aid healing by keeping skin clean and naturally removing dead tissue. You may be encouraged to gently move the affected area.
• Infection-fighting drugs. If the skin or blisters appear infected, your doctor may prescribe oral antibiotics.
• Clot-busting drugs. You may receive an intravenous (IV) injection of a drug that helps restore blood flow (thrombolytic), such as tissue plasminogen activator (TPA). Studies of people with severe frostbite show that TPA lowers the risk of amputation. But these drugs can cause serious bleeding and are typically used only in the most serious situations and within 24 hours of exposure.
• Wound care. A variety of wound care techniques may be used, depending on the extent of injury.
• Surgery. People who have experienced severe frostbite may in time need surgery or amputation to remove dead or decaying tissue.
• Hyperbaric oxygen therapy. Hyperbaric oxygen therapy involves breathing pure oxygen in a pressurized room. Some patients show improved symptoms after this therapy. But more study is needed.

Other Cold -Related Conditions

But frostbite isn't the only danger in the bitter cold. There are other serious health conditions to be worried about in frigid temperatures.

They include:

• Falls from walking on the snow and ice;
• Weather-related vehicle accidents;
• Heart attacks triggered while shoveling snow;
• and Other exposure injuries.

The best medicine to is stay informed about dangerous weather conditions by following local weather apps, dressing appropriately if you need to go outside and just staying home. If you need care, contact your JMH provider or come to the Emergency Room.