Frostbite is a serious condition where skin and underlying tissues freeze due to exposure to extremely cold temperatures, typically below 32°F (0°C). The appearance of frostbite changes significantly depending on its severity.
The Spectrum of Frostbite Colors
The initial stage of frostbite, known as frostnip, may appear red to purple, or lighter than the natural skin tone. The affected area often feels cold, tingly, and slightly painful. Upon rewarming, the skin can become reddened.
As frostbite progresses to a superficial stage, the skin may appear waxy or hardened, often pale, white, or bluish-gray. After rewarming, clear or milky blisters can form, typically within 12 to 36 hours. The skin might also feel warm internally, indicating tissue damage.
Deep frostbite affects all layers of skin and underlying tissues. The skin initially appears pale, waxy, or bluish. It then progresses to a mottled blue or purplish color, sometimes turning white or gray.
Severe deep frostbite can lead to the skin becoming hard, cold, and numb, with large blood-filled blisters appearing within 24 to 48 hours after rewarming. In the most severe instances, tissue death can occur, causing the affected area to turn black and hard. Color changes can be more challenging to observe on darker skin tones, where early signs might manifest as a gray or bluish hue, and advanced stages as dark, purplish, or black.
Accompanying Visual and Sensory Clues
Other characteristics accompany color changes. The affected skin may feel firm, waxy, or hard to the touch, and can be numb. This loss of sensation can make it difficult to realize the extent of the injury.
Swelling is common, particularly after rewarming, as fluids accumulate in the damaged tissues. Blistering is a hallmark of more severe frostbite, with clear blisters indicating milder damage and blood-filled blisters suggesting deeper tissue involvement. These blisters typically form hours after the affected area begins to rewarm.
Sensory changes often begin with tingling or stinging sensations, which progress to numbness as the freezing intensifies. Upon rewarming, intense burning pain is common. In severe deep frostbite, there can be a complete loss of sensation and difficulty moving the affected area, indicating potential muscle and joint involvement.
Immediate Steps for Suspected Frostbite
If frostbite is suspected, seek emergency medical attention immediately. The individual should be moved to a warm place to prevent further exposure to cold.
Protect the affected area by covering it loosely, but avoid rubbing or massaging it, as this can cause additional tissue damage. Remove any constrictive clothing or jewelry from the affected area before swelling occurs.
Gentle rewarming involves immersing the affected area in warm, not hot, water between 98.6°F and 102.2°F (37°C and 39°C) for about 15 to 30 minutes. Avoid dry heat sources like stoves or heating pads, as the numb skin can easily burn. Rewarming can be painful, and pain management may be necessary. If there is any risk of the affected area refreezing before reaching definitive medical care, rewarming should be delayed.