How do you prevent frostbite while hiking is mostly a question about three square inches of skin, because the tissue at risk is small and specific. The Centers for Disease Control and Prevention describes frostbite as usually affecting extremities such as the nose, ears, cheeks, chin, fingers and toes.
Cover those, cut the wind, stay dry, and keep circulation moving. That is nearly the whole of prevention.
The other half of this subject is what to do once it has started, where several instinctive responses make the injury worse.
Safety Disclaimer
This article is general information for hikers and is not medical advice. Frostbite is a tissue injury that needs medical attention. If skin is white, grayish-yellow, unusually firm or waxy, or numb, seek medical care rather than managing it yourself. Frostbite and hypothermia often occur together, and hypothermia is a medical emergency.
| Body part | Why it is at risk | What protects it |
|---|---|---|
| Nose and cheeks | Exposed, often uncovered | Balaclava or face covering |
| Ears | Thin tissue, poor circulation | Hat with full coverage |
| Chin | Missed by most hats | Neck gaiter pulled up |
| Fingers | Circulation shuts down early | Mittens over gloves |
| Toes | Tight boots and damp socks | Room to move, dry socks |
| Wrists | Gap between sleeve and glove | Overlap the layers |
Wind Chill Is the Driver
The threshold to know
The National Weather Service states that wind chill values near minus 25 degrees mean frostbite is possible within 15 minutes. That is a short window for a long hike.
Why wind matters more than temperature
Wind chill accounts for heat loss from the body to its surroundings. The National Weather Service gives minus 5 degrees with a 20 mile per hour wind as producing a wind chill near minus 30 degrees.
Which tissue it reaches
The National Weather Service notes that frostbite first affects exposed tissue where blood circulation may be limited, naming fingers, toes, nose and ears.
What that means on a route
Exposed ridges and summits are where frostbite happens, not the sheltered approach. Plan the covering for the windiest point rather than the trailhead.
Our guide to reading weather signs on the trail covers spotting a rising wind before you reach the exposed ground.
How Do You Prevent Frostbite While Hiking? Cover the Skin That Matters
Full face coverage is the single highest-return item in a cold wind. A balaclava covers cheeks, nose bridge, chin and ears in one piece, which no combination of hat and scarf does as reliably.
Goggles close the last gap. They seal the eye socket area that a balaclava leaves open, which is where exposed skin usually remains.
Overlap your layers at the wrists and ankles. A gap between cuff and glove is a direct wind channel onto skin with poor circulation.
Our roundup of balaclavas and face protection covers the coverage patterns, and our roundup of winter hiking goggles and eye protection covers the rest of the face.
How Do You Prevent Frostbite While Hiking in Hands and Feet?
These are the parts your body sacrifices first, so the fix is often not at the hands and feet at all. Warming your core restores circulation to the extremities.
Mittens beat gloves for warmth because the fingers share heat. A thin liner glove inside a mitten gives you dexterity without removing the whole system.
Tight is the mistake people make with both. A boot laced hard or a glove that compresses restricts the circulation you are trying to protect.
Damp is the other. Wet socks and sweaty glove liners conduct heat away, which is why a dry spare pair of each belongs in the pack.
Our guide to why hands get cold even with gloves covers the circulation side, and our roundup of hand warmers for cold weather hiking covers the supplement.
Spotting It Early, on Someone Else
Numbness means you have lost the sensation that would have warned you, so checking yourself is unreliable by the time it matters. Partners check each other’s faces.
The Centers for Disease Control and Prevention lists the signs as redness or pain in any skin area, a white or grayish-yellow skin area, skin that feels unusually firm or waxy, and numbness.
Redness or pain comes first and is the useful one. Pain is information, and skin that has stopped hurting has not improved.
Look at the nose, cheeks and ears of the person walking in front of you at every stop. They cannot see their own face and they cannot feel it either.
The Rewarming Rules, Including What Not to Do
- Get into a warm room or shelter. Out of the wind first.
- Remove wet clothing. It continues the injury otherwise.
- Warm under dry layers. Blankets and clothing.
- Use warm, not hot, water. On the affected areas.
- Do not rub or massage. And never rub with snow.
- Do not use direct heat. No heating pad, heat lamp, stove, fireplace or radiator.
- Do not walk on frostbitten feet or toes. Walking causes further damage.
- Seek medical attention. As soon as possible.
Those steps follow the Centers for Disease Control and Prevention guidance on frostbite, which specifies putting affected areas in warm rather than hot water, advises against rubbing the area with snow or massaging it at all, advises against a heating pad, heat lamp or the heat of a stove, fireplace or radiator, and states not to walk on feet or toes showing signs of frostbite.
The reason the don’ts exist is that numb tissue cannot report a burn, and frozen tissue is fragile. Rubbing damages it mechanically and direct heat damages it thermally, and the person feels neither.
Our roundup of hiking first aid kits covers what is worth carrying, and our roundup of emergency bivvy bags and shelters covers getting out of the wind when there is no room to get into.
A Field Problem Without a Good Answer
There is a genuine conflict in the backcountry advice, and it is worth stating plainly rather than glossing over. Rewarming tissue that then refreezes causes worse damage than leaving it frozen until you reach care.
That is why the decision depends on whether you can keep the area warm from here. If you cannot, the priority becomes getting out rather than warming up partway.
Walking is the other conflict, because the CDC advises against walking on frostbitten feet and self-rescue often requires it. That is a situation to avoid creating rather than to solve, and it argues for turning back early.
Either way this is a medical situation and not a field repair. Get medical attention as soon as possible, which the CDC states directly, and our guide to signaling for help in the backcountry covers summoning it.
Frequently Asked Questions
How do you prevent frostbite while hiking?
Cover the exposed extremities, cut the wind, stay dry, keep your core warm so circulation reaches your hands and feet, and avoid anything tight. The Centers for Disease Control and Prevention describes frostbite as usually affecting the nose, ears, cheeks, chin, fingers and toes, which is where the covering needs to be complete.
How quickly can frostbite happen?
Faster than most hikers expect in wind. The National Weather Service states that wind chill values near minus 25 degrees mean frostbite is possible within 15 minutes.
What are the early signs?
The Centers for Disease Control and Prevention lists redness or pain in any skin area, a white or grayish-yellow skin area, skin that feels unusually firm or waxy, and numbness. Redness or pain comes first, and numbness means the warning system has already gone.
Should I rub a cold, numb finger?
No. The CDC advises against rubbing the frostbitten area with snow or massaging it at all, because frozen tissue is fragile and the person cannot feel the damage being done.
Can I warm it by a fire or a stove?
No. The CDC advises against using a heating pad, heat lamp, or the heat of a stove, fireplace or radiator, and says to use warm rather than hot water on the affected areas. Numb skin cannot report a burn.
Why are mittens better than gloves?
Because the fingers share heat rather than each being insulated separately. A thin liner glove inside a mitten keeps some dexterity, and a glove tight enough to compress the hand works against circulation.
Can I keep walking on frostbitten toes to get out?
The CDC states not to walk on feet or toes that show signs of frostbite, because it causes further damage. That conflict with self-rescue is a strong argument for turning back before it reaches that point.
When should I see a doctor?
For any sign of frostbite, the Centers for Disease Control and Prevention advises seeking medical attention as soon as possible. Skin that is white, grayish-yellow, firm, waxy or numb needs care rather than observation, and frostbite frequently accompanies hypothermia, which is an emergency.
Sources
- Centers for Disease Control and Prevention. Preventing Frostbite.
- National Weather Service. Wind Chill Safety.
- Centers for Disease Control and Prevention. Recognizing Hypothermia.
