Frostbite happens when skin and underlying tissue freeze after exposure to cold temperatures, wind, or direct contact with freezing substances. At 0°F with a 15 mph wind, exposed skin can freeze in as little as 30 minutes. The combination of temperature, wind speed, moisture, and how long you’re exposed determines whether frostbite develops and how severe it becomes.
Cold Temperatures and Wind Chill
The most common way people get frostbite is simply being outside in freezing conditions for too long. But air temperature alone doesn’t tell the whole story. Wind strips heat from your skin far faster than still air does, which is why weather forecasts report “wind chill” alongside the actual temperature. At 0°F with a 15 mph wind, the wind chill drops to -19°F, and exposed skin can freeze within 30 minutes. As wind speeds increase or temperatures drop further, that window shrinks dramatically.
Your fingers, toes, ears, nose, and cheeks are the most vulnerable because they’re farthest from your core and have the most surface area exposed to the air. Blood vessels in your extremities constrict in the cold to keep your vital organs warm, which means less warm blood reaches those areas. That’s why your fingers go numb first.
Wet Skin and High Altitude
Moisture accelerates frostbite significantly. Wet skin freezes more quickly than dry skin because water conducts heat away from your body much faster than air does. Sweating inside your gloves or boots, stepping in slush, or getting caught in freezing rain all raise your risk even at temperatures that might otherwise feel manageable.
Altitude plays a role too. Thinner air at higher elevations means you breathe harder to get the same amount of oxygen, and the drier air pulls more heat from your lungs with each breath. Lower oxygen levels can also impair your judgment, making you less likely to recognize the early signs of frostbite or take precautions like putting on extra layers.
Contact With Freezing Substances
Frostbite doesn’t require cold weather at all. Direct contact with extremely cold substances can freeze skin in seconds, even indoors. Liquid nitrogen, dry ice, liquid oxygen, propane, butane, liquid ammonia, and refrigerant gases like freon are all common culprits. These substances are used in industrial settings, laboratories, medical procedures, and even recreational products. Compressed gas canisters, including those used for whipped cream chargers (nitrous oxide), have caused frostbite injuries when the pressurized gas rapidly cools on release and contacts skin.
Who Is Most at Risk
Certain people are more vulnerable to frostbite than others, even in the same conditions. If you’ve had frostbite before, your risk of getting it again is roughly doubled, because previously damaged tissue loses some of its ability to regulate blood flow. Conditions that reduce circulation, like Raynaud’s disease and diabetes, also make your extremities more susceptible.
Alcohol is one of the biggest risk factors. It dilates blood vessels near the skin’s surface, which makes you feel warmer while actually accelerating heat loss. It also impairs judgment, making you less likely to seek shelter or notice numbness. Data from Minnesota, one of the coldest U.S. states, shows that men between 15 and 64 account for the highest rates of cold-related emergency visits, with men aged 35 to 64 visiting the ER at a rate of 78 per 100,000 people. Altered mental status from alcohol, drugs, or psychiatric illness contributes to many of these cases.
Other risk factors include malnutrition and exhaustion (both of which impair your body’s ability to generate heat), being very young or very old, and homelessness. Certain medications that constrict blood vessels can also reduce blood flow to your extremities.
The Three Stages of Frostbite
Frostbite develops in stages, and recognizing the early signs gives you a chance to act before permanent damage occurs.
Frostnip is the mildest stage. Your skin changes color slightly and feels cold, then numb. This is your body’s warning signal. Frostnip doesn’t cause permanent tissue damage and reverses once you get warm.
Superficial frostbite goes deeper. The skin may feel paradoxically warm, which can be confusing. After rewarming, fluid-filled blisters typically appear within 12 to 36 hours. The skin is damaged but can usually recover.
Deep frostbite affects skin, muscle, and sometimes bone. Large blisters form 24 to 48 hours after rewarming, and the tissue may eventually turn black and hard as it dies. Deep frostbite can result in permanent loss of sensation, chronic pain, or amputation.
What to Do If Frostbite Develops
If you suspect frostbite, get out of the cold as soon as possible. Remove any rings, watches, or tight clothing before the area swells. Soak the affected skin in warm (not hot) water for about 30 minutes. For frostbitten ears or nose, apply warm, wet cloths for the same duration. Drink something warm and nonalcoholic, and take an over-the-counter pain reliever if needed, because rewarming can be intensely painful.
What you don’t do matters just as much. Don’t rub the skin with snow, your hands, or anything else. Rubbing frozen tissue causes microscopic ice crystals to tear through cells, making the damage worse. Don’t use direct heat sources like stoves, heating pads, hair dryers, or car heaters, because numb skin can’t feel when it’s burning. Don’t walk on frostbitten feet if you can avoid it. And don’t drink alcohol, which accelerates further heat loss.
If the skin remains numb, discolored, or blistered after rewarming, the injury needs medical attention. Deep frostbite always requires professional care.
Preventing Frostbite
Layering is the foundation of cold-weather protection. A moisture-wicking base layer (synthetic or merino wool) pulls sweat away from your skin. An insulating middle layer made of wool, fleece, or down traps heat. A waterproof, windproof outer shell keeps wind and moisture out. This system works because it addresses all three ways frostbite develops: cold, wind, and wetness.
Your ears are especially vulnerable, so wear an insulated, windproof hat that fully covers them. Mittens protect hands better than gloves because your fingers share warmth inside a single compartment. Choose waterproof, insulated boots, and pair them with moisture-wicking socks to keep your feet dry. For extreme cold, look for down-insulated jackets with a fill power of 500 to 900, with higher numbers indicating better insulation.
Beyond clothing, limit your time outside when wind chill values drop below -20°F, and check forecasts before heading out. Keep extra dry clothes available if you’ll be sweating or if conditions might turn wet. If any area starts to feel numb, get inside and warm up before frostnip progresses to something worse.