After 15 years of alpine climbing, I've treated a remarkable variety of injuries and illnesses in the mountains: blisters that took a client's entire foot out of commission, frostbitten fingers that the owner didn't realize were frozen until I pointed them out, a classic hypothermia progression in my own partner on a rainy bivouac, and multiple cases of altitude illness that would have become serious if the climbers hadn't recognized symptoms early. This article covers the first aid situations I actually encounter, with treatments that work in the field without professional medical equipment.
Blisters: Prevention and Treatment
Blisters are the most common climbing injury and one of the most preventable. They're caused by shear forces — your skin moves in one direction while the underlying tissue moves in another, creating separation between skin layers that fills with fluid. The key to prevention is reducing shear: proper boot fit, moisture management, and friction reduction.
Prevention starts with boot selection and break-in. Your boots should fit snugly in the heel and midfoot but allow toe movement. New boots that haven't been broken in will cause blisters even with perfect conditions. Sock selection matters — a single pair of purpose-made hiking/skiing socks with cushioning zones, or a thin liner plus outer sock system, typically outperforms improvised combinations. Change damp socks immediately; moisture dramatically increases blister risk.
Moleskin or paper tape applied to known hot spots before they become blisters is highly effective. Apply the tape to clean, dry skin, smooth it flat, and ensure all edges are firmly adhered. Once a blister forms, the treatment depends on size and location. Small blisters on non-weight-bearing areas should be left intact — the blister roof provides natural protection. Large blisters on weight-bearing areas should be drained: clean the area with antiseptic, pierce the blister at the edge with a sterile needle, drain the fluid without removing the roof, apply antibiotic ointment, and cover with a padded dressing that distributes pressure away from the blister center.
Frostbite: Stages and Field Rewarming
Frostbite severity is classified in degrees, but in the field, the practical distinction is between superficial frostbite (only skin and subcutaneous tissue affected) and deep frostbite (involving muscle and bone). The distinction matters because deep frostbite requires the same rewarming protocol as superficial but has a much longer recovery and higher risk of permanent tissue loss.
Superficial frostbite (frostnip): Skin appears white or grayish and is numb but pliable. Rewarming is simple: get out of the cold, remove wet clothing, and warm the affected area with body heat or ambient warmth. Frostnip rewarms without tissue damage if circulation returns promptly.
Superficial frostbite (first degree): Skin is white or yellowish, hard, and sensationless. After rewarming, it may blister but typically recovers fully. Rewarming technique: immerse the affected part in warm water (37-39°C, roughly body temperature) for 20-30 minutes until the tissue is soft and pliable. Do not use hot water — the frozen tissue cannot feel heat properly and can be burned easily.
Deep frostbite (second/third degree): Skin is white, waxy, and hard. Blistering after rewarming is extensive and blisters are dark (hemorrhagic). Deep frostbite requires the same rewarming protocol but may result in permanent tissue loss. Do not rewarm a frozen part if there's any chance it could refreeze — the freeze-thaw-freeze cycle is devastating to tissue. If you have a deep frostbite case and evacuation is possible, protect the frozen part from thawing until you reach definitive care.
Hypothermia: Recognition and Treatment
Hypothermia is a core body temperature below 35°C, and it's one of the most dangerous conditions in mountaineering because it can occur in temperatures well above freezing when wind and rain are present. The classic scenario is a wet, cold night at altitude with inadequate insulation — not necessarily the extreme cold that most climbers associate with hypothermia risk.
Mild hypothermia (32-35°C): Shivering, decreased coordination, impaired judgment, poor decision-making. The climber can still shiver actively and is still capable of self-rescue with assistance. Treatment: remove wet clothing, insulate aggressively, provide warm (not hot) sweet drinks, and add external heat sources (another person's body heat in a sleeping bag, chemical heat packs to core areas — armpits, groin, neck).
Moderate hypothermia (28-32°C): Shivering may decrease or stop, confusion and apathy increase, muscle rigidity develops, speech becomes slurred. The climber's judgment is significantly impaired and they may not recognize their own condition. Treatment: handle extremely gently — jostling can trigger cardiac arrhythmia in moderate hypothermia. Horizontal position, full insulation, active rewarming to core before extremities, evacuation is urgent.
Severe hypothermia (below 28°C): Unconsciousness, no shivering, rigid muscles, weak or absent pulse. This is a medical emergency requiring immediate evacuation and professional medical care. Do not assume someone with severe hypothermia is dead — they may appear dead but be recoverable with slow, careful rewarming. Handle with extreme gentleness and prepare for CPR if pulse is absent.
Dehydration and AMS Recognition
Dehydration at altitude is insidious — the usual signals (thirst, dark urine) are dulled, and the symptoms (headache, fatigue, dizziness) overlap with altitude illness. The practical approach: assume dehydration is contributing to any altitude symptom and treat it aggressively with electrolyte-containing fluids. For detailed hydration guidance, see our Hydration at Altitude guide.
Acute Mountain Sickness (AMS) presents with headache, fatigue, nausea, loss of appetite, and sleep disturbance — symptoms that overlap significantly with dehydration and exhaustion. The distinguishing factor is that AMS symptoms worsen when ascending further and improve with descent or rest at the same altitude. If symptoms don't improve with hydration, rest, and food, assume AMS and descend. For detailed AMS management, see our Altitude Sickness Complete Guide.
When to Evacuate
Field treatment has limits. Evacuate immediately (with professional medical support) for: moderate or severe hypothermia, deep frostbite, suspected HACE or HAPE, any head injury with loss of consciousness, suspected spinal injury, and any fracture that may require surgical intervention. Even with these conditions, begin field treatment immediately while evacuation is organized — the treatments described above don't stop when evacuation begins.
Related Articles
- First Aid Risk Assessor Tool — Evaluate risk levels for various conditions
- Emergency Shelter Building — Creating shelter for injured or hypothermic parties
- Hydration at Altitude — Prevention and treatment of dehydration