Picture this: your hiking partner has just twisted an ankle and can no longer walk. The nearest hospital is hours away. There's no cell signal. "I have no idea what to do" is one of the worst situations a hiker can be in. This piece walks through the basic field first aid you can actually carry out on a trail — for the injuries and conditions you're most likely to meet there.
Note: this article is general background, not medical instruction. Actual treatment decisions belong to doctors and qualified professionals.
"First aid" is not "treatment" — the framing you need first
The point of first aid on a mountain is not to fix the problem — it is to stop the problem from getting worse. A lot of people misread this. What the trail asks of you is to keep the patient in a state that lets them move to safety, or to buy time until proper rescue arrives.
If you suspect a fracture, you don't need a perfect splint. Don't move it, don't let it get worse, and reduce the patient's anxiety — those three things are the field goal. "I'm not a doctor, so I can do nothing" is the wrong response. So is the other failure mode: panicking into improvised "treatment" that's beyond what you actually know. Stay calm and do the things you can. That posture is the heart of first aid.
There's one more rule worth burning in early: secure the scene before you treat anyone. Before you run to the injured person, check for rockfall, unstable ground, or anything that could put you in the same trouble. "Rescuer becomes the second casualty" is a depressingly common pattern in mountain accidents.
Common trail problems and how to think about each
Sprains and bruises — the most common injuries you'll see
The most common hiking injuries are twisted ankles and bruises from falls. The standard field response is the four-step pattern widely known as RICE.
- R (Rest): stop moving the injured part.
- I (Ice): cool it. In the mountains you usually don't have ice — a towel wetted in a cold stream is the workable substitute.
- C (Compression): apply moderate compression with an elastic bandage or athletic tape to limit swelling.
- E (Elevation): if practical, raise the injured part above the level of the heart.
Note that recent medical thinking has begun to refine the RICE framework, particularly around how much cooling and how much rest is actually optimal. Treat the steps above as a field starting point and see a doctor once you're off the mountain.
Athletic tape and an elastic bandage weigh almost nothing and live happily in the bottom of a pack. Practising the basic wrap once at home pays back enormously the first time you need it for real.
Bleeding wounds — the basics of stopping the bleed
For cuts and scrapes that are bleeding, the most reliable method is direct pressure. Press a clean gauze or cloth firmly onto the wound with your hand. Most bleeding stops within a few minutes of steady pressure.
The classic mistake is lifting the gauze off repeatedly to check. Doing that breaks up the clot that's just starting to form, and the bleeding restarts. The rule is: keep the pressure on for at least 5 to 10 minutes.
If possible, clean your hands before you handle the wound, and use disposable gloves if you have them. The priority on the wound itself is to flush dirt out with running water — clean before you worry about disinfectant.
Heatstroke and hypothermia — early response
These aren't injuries in the obvious sense, but they are among the most lethal things that go wrong on a mountain. The shared rule is simple: the response in the first "something's off here" minutes is what determines the outcome.
If you suspect heatstroke, get the person into shade, loosen restrictive clothing, and — if they are able to swallow safely — give fluids with some salt. For hypothermia, get them out of the wind and rain, into dry layers, and offer warm drinks. In either case, if mental status is reduced, do not try to give them food or drink — the aspiration risk is real.
Either way, if symptoms aren't improving, or the level of consciousness is dropping, call for rescue right away. "Let's just wait and see a bit longer" is the form of indecision that turns these situations into deaths.
Note: there are dedicated YAMATOMO articles on prevention and response for heatstroke and hypothermia, with more depth than fits here.
What to put in your first-aid kit
"I don't know what to put in it" is the most common question. The honest answer is to put in items you actually know how to use, and recognise on sight. A piece of gear you can't operate under stress is just weight.
For a day hike, a reasonable baseline looks like this.
- Adhesive bandages (a small range of sizes).
- Sterile gauze pads and medical tape.
- An elastic bandage or athletic tape.
- A triangular bandage (splinting, bleeding control, sun cover — works for many things).
- Disposable gloves.
- Personal medications (non-negotiable if you have a chronic condition).
- A poison extractor (for the first response to bee/wasp stings).
- A small notepad and pen (for noting onset times and symptoms).
What medications you actually need, and in what quantity, depends entirely on your medical history. Talk to your own physician about what should travel with you.
The item people most often overlook is the notepad and pen. Writing down when and where symptoms appeared, and how they progressed, makes an enormous difference when you hand the patient off to rescue or medical staff.
Summary
What the mountain asks of you, in terms of first aid, is not advanced medical knowledge. It is calm judgement and a handful of basic techniques aimed at not making things worse. Secure the scene before you treat. Don't chase perfection — do the reliable things. And if you're uncertain, call for rescue early rather than late. These three principles change everything about how you respond when it matters.
First aid is not a one-time qualification. The knowledge fades; refresh it regularly, and ideally take a hands-on course. The Japanese Red Cross and regional alpine organisations both run wilderness-first-aid classes. Check the relevant organisation's official site for current schedules.
The days you think "I'll be fine" are precisely the days the preparation is worth most. For yourself, and for the people you walk into the mountains with — keep the basics in your hands.