Wilderness First Aid Kit: Build It Around Real Injuries

The Short Answer: Five Modules, About 1.5 lb (680 g)

Build the kit as five sealed modules. You can drop a module for a short day trip and add one for a group, without repacking anything.

Module A — Wound care. About 8 oz (225 g). Nitrile gloves, an irrigation device, gauze, non-adherent pads, roller gauze, cloth tape, adhesive bandages, wound closure strips, antiseptic wipes. This is the bulk of the kit because it is the bulk of the work.
Module B — Feet. About 2 oz (57 g). Hydrocolloid blister dressings, a roll of a genuinely adhesive tape such as a rigid strapping tape, moleskin or felt, fine-tipped tweezers, a small pair of nail scissors.
Module C — Medications. About 2 oz (57 g). An antihistamine, two analgesics, an anti-diarrhoeal, oral rehydration salts, an antacid, plus every prescription anyone in the group depends on — in labelled containers.
Module D — Trauma. About 5 oz (140 g). One tourniquet of a proven design, one pressure dressing, and the training to use both. This module is rarely opened and non-negotiable.
Module E — Temperature and paperwork. About 5 oz (140 g). An emergency bivy, a CPR barrier, a permanent marker, and a waterproof note card for patient assessment and times.

Five modules plus a lightweight roll-top or zip bag comes to roughly 24 oz — 1.5 lb (680 g). Two additions live at group level rather than in every pack: a 3 in (7.5 cm) elastic wrap at about 2 oz (57 g) and a 36 in (91 cm) malleable aluminium splint at about 4.5 oz (128 g), which together add another 6.5 oz (185 g) for the party.

Those weights are typical published figures for common items, rounded, and they are budget placeholders — not measurements we took. Weigh your own finished kit on a kitchen scale. That number is the only one that governs whether you actually carry it.

The ceiling matters more than the contents. A kit heavier than about 3 lb (1.4 kg) starts getting left in the car, and a kit in the car has an effectiveness of zero. Our first aid and medical hub sets out the wider category; this page is the build.

Why That Shape: The Injury Distribution the Kit Actually Meets

A kit should be weighted toward what happens, with one deliberate exception for what kills.

In practice, the overwhelming majority of what a backcountry kit ever treats is skin and feet: blisters, abrasions, small lacerations, splinters, stove burns, sunburn. Next, and far less often, come musculoskeletal problems — a rolled ankle, a strained knee, the fall that ends the trip and starts the carry-out. Then medical issues that have nothing to do with the terrain: allergic reactions, gastrointestinal illness, headache, dental pain, and whatever chronic condition someone in the party manages every day at home. Catastrophic trauma is genuinely rare.

That gives you a design rule with two halves.

Weight the volume by frequency. Wound and foot care should be most of the mass, because that is most of the use. If your kit has more tourniquets than gauze, it is built for a fantasy.

Weight one module by consequence instead. Arterial bleeding from a limb can kill in minutes. Nothing else in the backcountry gives you that little time with that much leverage. One tourniquet and one pressure dressing therefore earn 5 oz (140 g) on consequence alone, in the same way a smoke alarm earns its place in a house that has never burned.

Everything else is a judgement about your trip. A day hike within 3 miles (5 km) of a trailhead on a mild afternoon is a different medical problem from a three-day traverse at 9,000 ft (2,700 m). The working definition of wilderness medicine is care delivered when definitive treatment is more than one hour away — and the further past that hour you are, the more the kit shifts from covering wounds to properly cleaning them, and from treating injuries to keeping someone warm, hydrated and documented for a long time.

Module A — Wound Care, and the Irrigation Arithmetic Nobody Does

In town, you cover a wound and a clinician cleans it within the hour. In the backcountry, you are the cleaning, and whatever you leave in the wound stays there for a day or more. Irrigation is therefore the single most important thing this module does, and it is the thing most kits cannot do at all.

The arithmetic. A contaminated wound wants a generous volume of clean water delivered under enough pressure to lift debris out — on the order of 1 quart (about 1 L) for a typical dirty laceration, more for anything ground-in. One quart of water weighs 2.2 lb (1 kg) and is 25% of the one gallon (3.8 L) per person per day planning figure used in household preparedness. So irrigating one wound properly costs a quarter of someone's daily water. Know that before you are standing there rationing.

Use water you would drink. If the only water available is untreated, disinfect it first: bring it to a rolling boil for 1 minute, or 3 minutes above 6,500 ft (2,000 m), per the EPA's emergency disinfection guidance, and let it cool. Our water storage guide covers the treatment options in full.

Pressure, cheaply. A 20 mL irrigation syringe weighs about 0.5 oz (14 g). A bottle cap with a small hole drilled in it, fitted to the mouth of a standard drinks bottle, weighs almost nothing and turns your water bottle into an irrigation device. Either beats pouring, which mostly wets the wound.

What goes in the module:

Nitrile gloves, 3 pairs. One pair covers one patient badly. They weigh a third of an ounce a pair.
Irrigation syringe or drilled bottle cap.
Sterile gauze, 4 x 4 in (10 x 10 cm), six pads. The workhorse. Cleaning, packing, padding, absorbing.
Non-adherent pads, 3 x 4 in (7.5 x 10 cm), two. For burns and abrasions, where ordinary gauze bonds to the surface and tears it off at the next change.
Roller gauze, 3 in (7.5 cm) wide. Holds dressings on limbs where tape will not stick.
Cloth surgical tape, 1 in (2.5 cm). Choose cloth over plastic; it conforms and it sticks to damp skin.
Adhesive bandages, about ten, in two or three sizes. Ten, not two hundred.
Wound closure strips. For a clean-edged cut on a low-tension area, after irrigation. Not for anything contaminated.
Antiseptic wipes and a small povidone-iodine. For intact skin around the wound. The wound itself gets water and volume.

The decision that matters more than any item: an irrigated, covered, open wound that gets infected is a problem. A wound you closed over trapped dirt is a worse one. In the field, irrigate thoroughly, dress loosely, check it daily, and get it looked at. Wound management judgement is safety-critical and depends on the injury in front of you — see the disclaimer.

Module B — Feet: The Injury That Ends the Most Trips

Blisters are not a minor category. They are the most common reason a group turns back, and a blister that opens and gets infected 8 miles (13 km) from the road is a real medical problem. Two ounces of foot kit prevents more incidents than the rest of the bag treats.

Treat hot spots, not blisters. The moment you feel friction, stop and tape. Stopping for three minutes at mile 2 saves you the whole afternoon. Most people push on for another hour and pay for it.

What earns its place:

Hydrocolloid blister dressings, four. They cushion, they seal, and they stay on through several days and several washes. They are the one blister product worth its price.
A rigid strapping tape. The cloth tape in Module A holds dressings; a rigid athletic-style strapping tape is what actually stays stuck to a sweaty heel for eight hours. Pre-cut a few strips and carry them stuck to a small square of backing rather than carrying the whole roll.
Moleskin or adhesive felt. Cut a doughnut with the hole over the blister so the pressure lands on the ring, not the roof.
Fine-tipped tweezers. For splinters, thorns, and tick removal — grasp the tick as close to the skin as you can and pull steadily upward without twisting, per CDC guidance.
Small scissors or nail clippers. A long toenail on a descent produces a bruised nail bed that takes months to grow out.
A spare pair of dry socks, carried in the pack rather than the kit. Wool or synthetic. Dry feet blister far less than wet ones.

On draining a blister: mainstream first aid guidance is to leave an intact blister alone where you can, because the roof is a sterile dressing. If it is large, weight-bearing and certain to burst, the field compromise is to drain it at the edge with a sterilised point, leave the roof in place, and dress it. If you do open one, you have created a wound and it gets Module A treatment and daily checks.

The prevention side is boring and it works: boots broken in before the trip, socks that fit, liner socks if you are prone, feet dried at every break, and pace managed on descents where friction and heat are highest.

Module C — Medications: Two Ounces That Do the Most Work

Ounce for ounce, medications are the most useful thing in the kit and the most commonly under-packed. Two ounces of blister-packed tablets treat more real incidents than anything else you carry.

Carry these categories, and follow the label on every one:

An antihistamine. For allergic reactions, insect stings and hives. Note that sedating antihistamines impair judgement and balance — which matters if the patient still has to walk out.
Two analgesics with different mechanisms — typically an NSAID such as ibuprofen and acetaminophen (paracetamol). Never exceed the daily maximum printed on the packet, and take particular care with acetaminophen, where the ceiling is a hard one. NSAIDs are a poor choice for a dehydrated patient or anyone with a history that contraindicates them.
An anti-diarrhoeal, plus oral rehydration salts mixed strictly as the packet directs. In gastrointestinal illness, the dehydration is usually the problem, not the symptom — fluid and electrolytes matter more than stopping the symptom.
An antacid.
Every prescription anyone in the group depends on, in its original labelled container, with dose and strength written on the group's medical card.
An epinephrine auto-injector if anyone is prescribed one — and everyone in the party should know where it lives and how it is used. For anaphylaxis the injection goes into the outer thigh, and the patient needs emergency medical care afterwards even if they improve, because symptoms can return hours later.

Packing. Keep unit-dose blister packs rather than loose pills in a bag. Loose tablets are unidentifiable under stress, degrade faster, and are legally awkward to be carrying. Write the expiry date on the outside of the module in permanent marker so an audit takes ten seconds.

Three honest limits. First, giving medication to another adult — and especially to someone else's child — carries legal and medical considerations that vary by jurisdiction; know your own position before you are asked. Second, we do not publish doses; the packet does, and the packet is current. Third, self-directed antibiotic stockpiles chosen from internet searching are a way to make a treatable problem worse. If you have a genuine need for an emergency supply — remote travel, an expedition, a chronic condition — that is a conversation with your own prescriber. All of this is jurisdiction-dependent and medical; see the disclaimer.

Module D — The Trauma Layer, and the Training That Makes It Work

This module gets opened once a decade, if ever. Carry it anyway, because the time window on serious limb bleeding is measured in minutes and there is nothing else you can do about it with your hands.

One tourniquet of a proven design. Buy from a supplier who can tell you where the unit came from. Counterfeits of well-known trauma tourniquets circulate widely through marketplace sellers and they fail under load — the windlass snaps or the strap tears at exactly the moment the device is doing its job.

Buy two. Train with one until it is worn out. Carry the other sealed. A tourniquet you have never tightened is an unknown device, and the first time you unwrap one should not be in the dark with someone bleeding.

Application, matching mainstream published guidance: place it 2–3 in (5–8 cm) above the wound and never directly over a joint; tighten until the bleeding stops, not until it slows; secure the windlass; and write down the time of application. It hurts a great deal — that is expected and is not a reason to loosen it. Once applied, a tourniquet is not removed in the field by an untrained rescuer. Where the bleeding is in a location a tourniquet cannot reach — the groin, the armpit, the neck — the answer is direct pressure and wound packing, which is a hands-on skill taught in a bleeding-control class.

One pressure dressing. A compressed gauze dressing with an integrated elastic wrap gives you a one-handed way to convert direct pressure into a dressing that holds it for you, so your hands are free for the next problem.

Order of attack, in the order that kills fastest: life-threatening bleeding, then airway, then breathing, then circulation, then temperature. And before any of it, the scene. Moving water, rockfall, traffic, downed lines, carbon monoxide — you are no use as a second patient.

The CPR numbers you should already know, because you will not be reading a card: compressions at 100–120 per minute, at least 2 in (5 cm) deep for an adult and not more than about 2.4 in (6 cm), full recoil between compressions, interruptions as short as possible. If you are untrained or unwilling to give rescue breaths, compression-only CPR is the recommended alternative. You cannot learn depth from a paragraph — take a hands-on class from the American Red Cross or an equivalent provider. A half-day course outperforms a thousand dollars of gear.

Module E — Temperature, Shelter and the Paperwork

Injured people get cold, and they get cold in weather that felt fine while they were walking. They stop moving, they often end up lying on the ground, and if there is blood loss involved their ability to hold temperature falls further. In a long wait for help, temperature is frequently the actual threat — not the injury that started it.

An emergency bivy, about 3.5 oz (100 g). Not the thin foil sheet, which tears in the wind and shreds on the first rock. A sealed-seam reflective bivy survives a night and contains a patient.
Ground insulation. This is treatment, not comfort. A sitting pad, a foam pad, a pack, spare clothing — anything between the patient and the ground, which conducts heat away far faster than the air does.
A CPR barrier, half an ounce.
A permanent marker and a waterproof note card.

The figures worth memorising. Mild hypothermia begins below a core temperature of about 95°F (35°C); shivering that stops in someone who is still cold is a deterioration, not an improvement. Heat stroke means a core temperature around 104°F (40°C) or higher with altered mental status — confusion plus hot skin is the signal to start aggressive cooling and arrange transport immediately, not to go looking for a thermometer. CDC Emergency Preparedness is the reference for both. For burns, cool with cool running water for 10 to 20 minutes — not ice — remove rings and watches early before swelling sets in, then cover with a clean non-adherent dressing. No butter, no ointment, no ice on a fresh serious burn.

At altitude, acute mountain sickness becomes a real consideration above roughly 8,000 ft (2,400 m). The only reliable treatment for a deteriorating altitude patient is to go down, and it is not a decision to defer until morning.

The paperwork is a medical item. Write a structured note: the patient's problem, the time it happened, what you did and when, and two timed sets of vital signs so a rescue team can see the trend rather than a snapshot. "He seemed worse" is not information. Pulse rate at 14:10 and again at 14:40 is. Record medication given, times, allergies, and the tourniquet time if there is one.

Warmth is a bushcraft problem as much as a medical one — starting a fire in wet conditions is a first aid skill when the patient is hypothermic and the wood is soaked.

Scaling: Day Hike, Group Weekend, Vehicle, Household

One kit does not cover every trip. Scale by how long help will take, how many people you are responsible for, and how much weight you are already carrying.

Personal day kit — about 10–12 oz (280–340 g). Modules A (reduced to four gauze pads and one roll of tape), B and C, plus gloves and an emergency bivy. Add the trauma module if you are going somewhere with sharp tools, hunting, or riding. This is the kit that goes in every pack, every time, because it costs almost nothing to carry.

Group multi-day kit — about 1.5–3 lb (0.7–1.4 kg). The full five modules, plus the elastic wrap and the malleable splint, plus more of the consumables that actually get used: gauze, tape, blister dressings, gloves. Consumables scale with party size; the splint and the shears do not. A party of four does not need four splints, and it absolutely needs more than four pairs of gloves.

Vehicle kit. No meaningful weight limit, so carry everything above plus a larger trauma stock, a full set of splints, an irrigation reservoir, a blanket and a headlamp. One warning: a kit that lives in a car cooks. Summer cabin temperatures degrade adhesives, dry out alcohol wipes, and shorten medication shelf life. Audit a vehicle kit twice a year and treat its expiry dates as optimistic.

Household kit. The medical layer at home is different again. It is dominated not by trauma but by prescription continuity — a rolling buffer of medication arranged with your own pharmacist, a written list of doses and strengths for each person, and a plan for refrigerated medication and powered medical equipment during a long outage. Sizing that power draw honestly is covered in backup power for a home outage. The medical module inside a grab bag is covered in the 72-hour emergency kit.

The weight budget, made explicit. A loaded pack an untrained adult can carry a few miles is about 20% of body weight — 32 lb (14.5 kg) for a 160 lb (73 kg) adult. A 1.5 lb (680 g) kit is 4.7% of that. Doubling it to 3 lb costs you 4.7% more, which is roughly a fleece or a litre of water. That trade is usually worth making for a group and rarely worth making solo.

Packing, Labelling, and the Six-Month Audit

How the kit is organised decides how fast you can use it, and organisation is the cheapest performance gain available.

Pack by module, in coloured or labelled pouches, and write the contents on the outside in permanent marker. In an incident you are looking for a category — "bleeding", "blister", "drugs" — not for a specific item. A single compartment with everything loose means dumping the kit on the ground in the rain.

Waterproof twice. The pouch keeps things tidy; a zip-seal bag inside keeps gauze sterile after your water bladder leaks. Sterile packaging that has been wet is no longer sterile.

Put the trauma module where one hand can reach it without opening the main kit — an outside pocket, or its own pouch on the hip belt. Bleeding control is the one thing where seconds matter, and it is the one thing you should never have to unzip three layers to find.

Print an inventory card and laminate it. List every item, the quantity, and the earliest expiry date in the kit. Someone else may have to use your kit on you, and they did not pack it.

The six-month audit, on a fixed date. Put it in the calendar; drifting to "when I remember" means never.

Check every expiry date against the inventory card.
Replace anything used and not replaced — this is the most common failure by a wide margin.
Peel-test the tape and the adhesive dressings. If the tape does not grip your own forearm, it will not grip a sweaty ankle.
Check the tourniquet for strap fraying, windlass cracking and clip deformation, and confirm it is still the sealed one rather than the training one.
Confirm gloves are intact and unpowdered residue has not made them brittle.
Re-read the agency pages you rely on. Guidance is revised; a laminated card from 2019 is not evidence.

Pass condition for the audit: one expired item means the whole kit gets a full pass-through, not a spot fix. An expired item is a signal that the kit has not been maintained, not an isolated fault. Our approach to checking gear claims — including what we do and do not test on medical products — is set out in how we test and gear tested.

Drills With Pass Conditions

You do not know whether you can do something until you set a standard and fail it a few times. Each drill below has a condition and an explicit pass line. Repeat each until it is boring.

Blind inventory. Empty the kit on a table. Name every item and what it is for, in under 2 minutes. Pass: every item named. Fail: any item you cannot explain — learn it or remove it. There is no third option, and this is the drill that shrinks most people's kits by a third.
Tourniquet, self-application, one-handed. With your training tourniquet, apply it to your own upper thigh with one hand in under 60 seconds. Repeat with the other hand. Pass: windlass locked and secured, time noted, and you could not have tightened it further. Fail: anything you would honestly describe as "close enough".
Gloves on wet hands. Wet your hands, then glove up in under 30 seconds without tearing a glove. Fail: a torn glove, or a second pair used. Least glamorous drill on the list, and one of the most predictive.
Two minutes of CPR. On a manikin or a training device, hold 100–120 compressions per minute at full depth for 2 continuous minutes. Pass: rate and depth hold to the end. Most people discover here how fast they tire — which tells you how urgently you need a second rescuer, not that you are unfit.
Irrigation, measured. Irrigate a mock wound (a marked patch of skin, or a grapefruit) with 1 quart (1 L) of clean drinking water under pressure, then dress it. Pass: the syringe or cap never touched the wound, the dressing went on clean, and you can state what that irrigation cost you — 2.2 lb (1 kg) of carried water, a quarter of a person's daily allowance.
Improvised splint. Splint a forearm in under 10 minutes using only what you are carrying that day. Pass: joints above and below immobilised, circulation checked before and after, and you would genuinely walk 3 miles (5 km) wearing it.
Find it in the dark. In full darkness, with gloves on, retrieve the tourniquet and the gauze from your pack in under 30 seconds each. Pass: both found without emptying the pack. Fail: you turned on a light to find the light.
SOAP note from memory. Write a patient report — subjective, objective, assessment, plan — with two timed sets of vital signs, in under 5 minutes. Pass: someone else could read it and tell you what changed and when.
The evacuation call. Out loud, state your location in coordinates, the patient's problem, the number of people with you, and what you need. Pass: under 60 seconds, without looking up your own coordinates twice.

If a drill feels artificial, that is the point. Every one of them is a task you will be asked to perform once, badly, under time pressure, unless you have performed it fifty times calmly.

Common Mistakes and Failure Modes

These are failure modes, not moral failings. Nearly everyone commits several on the way to a kit that works.

Buying the kit instead of the training. The kit is the cheap half and the half that does nothing on its own. A trained person with a bandana outperforms an untrained person with a 300-piece bag, every time.
Buying on piece count. "300 pieces" describes adhesive bandages, not capability. Count categories, not items.
No irrigation capability. The most common and most consequential gap. A kit that can cover a wound but not clean it is a kit that hands a clinician an infected wound a day later.
One pair of gloves. Or none, because they got used on a blister in March and were never replaced.
Never opening the packaging. Unwrapping a tourniquet for the first time during an emergency is a training decision you made months earlier by not training.
Treating the injury and ignoring the evacuation. The bandage takes four minutes. The 3 mile (5 km) carry-out with someone who cannot bear weight takes the rest of the day, and it is the part nobody planned. Decide early, in daylight, while the patient can still walk — that is a materially different situation from deciding at 2 a.m.
Ignoring temperature. Ground insulation is treatment. A patient lying on cold rock is losing heat faster than anything you are doing is replacing it.
Letting the kit cook in a vehicle. Heat cycling kills adhesives and shortens medication life. Anything that has lived through a summer in a car needs checking, not assuming.
Loose pills in a bag. Unidentifiable under stress, faster to degrade, and awkward to explain. Keep the labels.
Carrying a splint and no tape. Or shears and nothing they can cut. Kits assembled item by item without a scenario walk-through end up with orphaned equipment.
Skipping the boring skills. Foot care, hydration, sun protection and pacing prevent more incidents than any trauma item will ever treat.
Assuming phone coverage. Plenty of terrain has none, and a dead phone has less. Check forecasts from the National Weather Service before you leave, not a summary app's icon, and know before departure whether your route has coverage or whether you need a satellite messenger.

What We Will Not Carry, and Where the Limits Are

A build guide should be as clear about exclusions as inclusions, with the reason attached.

Snakebite extractors, suction devices, cutting and constriction bands. Mainstream guidance does not support them and some cause additional harm. For a venomous bite in the United States: keep the person calm, remove rings and tight clothing, keep the limb roughly at heart level, and get to a hospital.
Suture kits for untrained use. Field wounds are contaminated, and closing one seals the contamination in. Thorough irrigation plus an open or loosely approximated dressing produces a better outcome in nearly every scenario a layperson will meet.
Unverified tourniquets from marketplace sellers. Covered above. This is the one item where provenance is worth paying for.
Self-directed antibiotic stockpiles, including veterinary and aquarium products. Wrong drug, wrong dose, wrong diagnosis, no way to monitor the result.
Kits sold through fear. No countdowns, no implied collapse, no bundle that only makes sense if you assume help is never coming. If a product needs a scenario that dramatic to justify its price, the product is the problem.

The limits of this page, stated plainly. We do not test clinical outcomes, run trials on dressings, or generate our own resuscitation data. Every safety-critical figure here — CPR rate and depth, tourniquet placement, burn cooling times, hypothermia and heat stroke thresholds, boil times — is taken from published guidance from the American Red Cross, CDC Emergency Preparedness, Ready.gov, FEMA and the EPA, and linked at the point of use. Check each against the source before you rely on it; guidance is revised, and the agency page is always more current than any article about it.

Medical care, medication handling and Good Samaritan protections are jurisdiction-dependent. Nothing here is a diagnosis, a prescription, or a substitute for training and a licensed clinician — see our disclaimer, which sets out real limits rather than legal decoration, and our editorial standards for how we handle figures we cannot source.

The next step is a course, not a purchase. A hands-on CPR and AED class first, then bleeding control, then a two-day wilderness first aid course of roughly 16 hours — most of it scenario work outdoors, where the real content is the decision-making rather than the protocols. Then build this kit and learn every item in it. More context in the first aid hub, the full library in all guides, and a sequenced path through the rest of your preparedness in start here. If a figure on this page is wrong, or a method failed in your conditions, tell us — corrections take priority over everything else we publish.