Montana winters are long, and your feet take a lot of the punishment. They're far from your heart, they often sit in boots that get wet, and they can go numb before you notice anything is wrong. The American College of Foot and Ankle Surgeons notes that the feet, hands, ears and nose "are particularly prone to frostbite due to their location away from the body's core."1
This guide covers three cold injuries that affect the feet: frostbite, chilblains and trench foot. It explains how to tell them apart, what to do in the moment, and how to prevent them, whether you're shoveling the driveway in Butte, hunting outside Ennis or skiing near Bozeman.
What Is Frostbite?
Frostbite is "an injury to the body that is caused by freezing."2 When it gets cold enough for the water in your tissues to freeze and form ice crystals, cells can die.1 MedlinePlus notes that frostbite can cause permanent damage, and in severe cases it can lead to amputation.3
Cleveland Clinic describes three stages:4
- Frostnip is the early warning stage. Skin feels cold, sore and painful, may look red to purple, and may tingle. The skin damage is temporary.
- Superficial frostbite brings a "pins and needles" feeling, stinging and swelling. Blisters may form after the area is rewarmed. This stage needs medical attention.
- Deep frostbite causes total numbness and trouble moving the area. Skin may turn black, a sign that cells have died, and large blisters can form.
MedlinePlus adds that frostbitten skin "may turn white or grayish-yellow" and "may feel firm or waxy" to the touch.3
What to Do If You Suspect Frostbite
These first-aid steps come from the CDC, MedlinePlus and Cleveland Clinic.2,3,4 They are a bridge to medical care, not a replacement for it.
- Get somewhere warm as soon as you can, and take off wet socks and footwear.
- Don't walk on frostbitten feet or toes if you can avoid it.
- Rewarm in warm, not hot, water. ACFAS suggests about 100°F;1 Cleveland Clinic gives a range of 98.6 to 102.2°F.4
- Don't rub or massage the area, and don't rub it with snow.3
- Skip direct heat such as heating pads or a hair dryer. Numb skin "can be easily burned."1,2,3
- Don't let the area refreeze after you warm it. Avoid cycles of warming and refreezing.4
What Are Chilblains?
Chilblains, also called pernio, are "small patches of inflamed skin" that show up after exposure to cold or damp air that isn't freezing.5 The CDC says they're caused by repeated exposure to temperatures between freezing and 60°F, which damages small blood vessels in the skin.2 That means they can show up on cool, damp days, not just in deep cold.
They often appear on the toes. Signs include painful, swollen patches that may look shiny, red, blue or purple, with itching, burning and sometimes blisters.5 Cleveland Clinic lists low body weight, damp climates, smoking, tight clothing and conditions such as lupus or Raynaud's phenomenon as risk factors.5
Most chilblains clear up on their own within one to three weeks.5 In the meantime, the CDC advises not scratching, warming the skin slowly, and keeping any blisters clean and covered.2
See a provider if chilblains last longer than three weeks, if you have diabetes and get chilblains on your feet, or if you notice fever, chills or pus.5
What Is Trench Foot?
Trench foot, or immersion foot, is "an injury of the feet resulting from prolonged exposure to wet and cold conditions."2 Long hours in wet socks or soaked boots, on a hunt, a work site or a wet trail, are exactly the conditions to watch for.
The CDC lists reddened skin, numbness, tingling pain, leg cramps, swelling, blisters or ulcers, and bleeding under the skin. Severe cases can lead to gangrene.2 First aid is to take off wet boots and socks, dry the feet, and avoid walking on them.2 Then get your feet checked.
Who Is at Higher Risk?
Anyone can get a cold injury, but Cleveland Clinic notes higher risk for people who:4
- Are younger than 18 or older than 65
- Have diabetes, peripheral vascular disease or Raynaud's syndrome
- Smoke
- Don't have adequate shelter or warm clothing
If you have diabetes, take extra care. The NIDDK explains that diabetes can cause nerve damage that makes you "lose feeling in your feet," and can lower blood flow so that sores and infections heal slowly.6 That means a cold injury can go unnoticed. NIDDK recommends checking your feet every evening when you take your shoes off, and calling your provider right away for a cut that won't heal, signs of infection, or skin that darkens.6 Learn more about diabetic foot care at Big Sky Foot & Ankle.
How to Protect Your Feet This Winter
- Keep feet warm and dry. ACFAS says frostbite "can be prevented by limiting exposure and keeping the feet as warm and dry as possible."1 Change out of wet socks as soon as you can.
- Wear lined, waterproof boots in winter, as NIDDK advises.6 Add warm socks and layers.4
- Avoid tight socks and boots. Clothing that isn't tight helps maintain circulation.4
- Limit your time outside in very cold weather and take warm-up breaks indoors.4
- Wear socks to bed if your feet get cold, rather than using a heating pad or hot water bottle, especially if you have diabetes.6
- Check your feet every day, and after time outdoors, for color changes, blisters, sores or swelling.6
The Bottom Line
The best protection against frostbite, chilblains and trench foot is keeping your feet warm and dry in insulated, waterproof footwear that isn't too tight. Know the warning signs: numbness, waxy or discolored skin, or blisters after cold exposure. Rewarm gently and get care quickly for anything beyond mild frostnip. If you have diabetes or poor circulation, check your feet every day this winter.
If cold-weather foot problems keep coming back, or you have lingering pain, numbness or skin changes, our podiatrists can take a look. Request an appointment and our team will follow up within one business day. You can also find your nearest office on our locations page.
This article is for general education and isn't a substitute for medical advice. Talk with a podiatrist or your doctor about your own symptoms.
Sources
- Frostbite. American College of Foot and Ankle Surgeons (FootHealthFacts.org). www.foothealthfacts.org
- Cold-related Illnesses in Workers. CDC, National Institute for Occupational Safety and Health, reviewed 2026. www.cdc.gov
- Frostbite. MedlinePlus, U.S. National Library of Medicine, updated 2025. medlineplus.gov
- Frostbite: Signs & Symptoms, Stages, Treatment & Prevention. Cleveland Clinic, 2023. my.clevelandclinic.org
- Chilblains (Pernio). Cleveland Clinic, 2024. my.clevelandclinic.org
- Diabetes & Foot Problems. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). www.niddk.nih.gov