In subzero winter months, frostbite is a serious concern. Your fingers, toes, nose, ears, cheeks and chin should all be bundled up to avoid damage.

What is frostbite? Mayoclinic.com defines frostbite as “[when] the skin and body tissue just underneath it freezes. Your skin becomes very cold, then numb, hard and pale.” There are three stages of frostbite:

1. Dubbed as “frostnip,” this relatively minor stage of frostbite is characterized by red appendages. Irritated skin feels cold, and is followed by numbness. Frostnip does not permanently damage the skin, and can easily be fixed with the first aid treatment of slowly warming your skin with warm water.

2. Superficial frostbite occurs when the cold and numbness of frostnip begins to gradually feel warm in the affected skin. This stage is more serious, but can still be treated with first aid measures. However, 24 to 36 hours after thawing the skin, fluid-filled blisters may form.

3. Deep frostbite is a serious concern and requires immediate medical attention. Characterized by blackening of appendages, it damages the skin, tissues, muscles and bone. It can lead to complications such as nerve damage and infection. Not to mention amputation may be required.

The best counter for frostbite is prevention. Wear warm clothing and limit outdoor exposure on cold days.