What to pack in a hiking first aid kit

Most of the weight in a hiking first aid kit goes toward the injury you will almost certainly face on trail. Blisters. Everything else is insurance.

Why blisters eat half your kit

Adventure Medical Kits notes that the majority of items in a typical hiking first aid kit are devoted to foot care because it is the most frequent trail ailment by a wide margin. A hot spot caught early is a five-second fix. The same spot ignored for another mile turns into a drained, padded, wrapped production that takes up half your break.

The layered approach:

• Moleskin: cut to size and apply at the first hint of rubbing. This is prevention, not treatment.
• Hydrocolloid dressings (GlacierGel style): for an intact blister. The gel pad cushions without sticking to the wound roof, which you want to leave in place.
• Doughnut pad: cut a donut shape from moleskin so the hole sits over the blister, taking pressure off the dome. Cover with a non-adherent dressing and secure with medical tape.

Wound cleaning: pressure matters more than antiseptic

A cut on the trail has one job before you close it: get the debris out. Antiseptic alone does not do that. Mechanical irrigation does.

A 10–20 ml syringe with a 18- or 19-gauge tip delivers the 8–15 psi that clears bacteria and trail grit from a laceration. A 35cc syringe with a 19-gauge needle produces approximately 8 psi; a 12cc syringe with a 22-gauge needle produces approximately 13 psi. The AHCPR recommends 10–15 psi for wound irrigation. Pressure above 15 psi can damage tissue, so more force is not better. Clean potable water works in the field; dilute povidone-iodine (1%) is an upgrade if you carry it.

After irrigation:

1. Pat dry with gauze.
2. Apply a thin layer of antibiotic ointment.
3. Use closure strips (Steri-Strips or equivalent) to pull wide cuts together.
4. Cover with a non-adherent dressing and secure with tape or a self-adhesive bandage.

Medications: the core four

Commercial first aid kits are often light on medications because regulations prevent most from including OTC drugs. Buy a pre-made kit for its wound and blister hardware, then build your own med pouch separately.

Carry at least two doses of each for every person in the group:

Ibuprofen covers pain and inflammation. Diphenhydramine handles allergic reactions and doubles as a sleep aid at altitude. Loperamide stops a stomach emergency from becoming a full evacuation. Hydrocortisone 1% cream quiets contact reactions from plants and insect bites. None of these are optional if someone in your group has a known allergy risk, a prescription inhaler, or an EpiPen.

Trauma basics: scale with remoteness

The question is not "do I need trauma supplies?" but "how long until EMS arrives if something goes wrong?"

NOLS's wilderness kit checklist covers 27 items and specifically includes a 12cc irrigation syringe, a SAM splint, wound closure strips, tincture of benzoin swabs, moleskin, triangular bandages, nitrile gloves, and a rescue mask. That list reflects the threshold where backcountry seriousness warrants genuine trauma readiness.

A satellite communicator is not a first aid item, but it belongs in the same pocket. The fastest trauma care on a remote trail is the helicopter you called before dark.

Sizing by group and trip length

Tools are shared across the group. Consumables are not.

The guiding formula: how long until EMS or a hospital? Multiply that time by the number of people. Then ask whether your kit can handle the three most likely problems for your terrain and weather.

Starting with a pre-made kit

A commercial kit is a valid starting point, not a finished product. Most are well-stocked for wound care but light on medications. The workflow:

1. Choose a kit sized for your typical trip (day, overnight, or extended backcountry); a day-size option like the Adventure Medical Kits Ultralight/Watertight .7 covers the first tier.
2. Inventory it against the categories above: blisters, wound care, medications, trauma layer.
3. Add your own med pouch with the four core OTC drugs and any personal prescriptions.
4. Check expiration dates before every season.
5. Restock consumables (gauze, closure strips, gloves, bandages) after every trip they are used on.

Never pack anything you have not learned to use. A tourniquet applied incorrectly causes harm. If your kit includes one, practice with it before the trip.

For specific kit options at each tier, see our guide to the best hiking first aid kits.

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