A lot of medical necessities are covered by taking care of the previous priorities. E.g., if you built a fire and made a shelter, you’ve solved your hypothermia problem for as long as the firewood holds out.

What’s left for Type I provision are things like sunscreen and lip balm, a small number of OTC meds for pain control and minor maladies, and the like.

But before I break a rule, and give you a list of stuff, there’s something you have to do to prepare long before you need that stuff:

You will not, after a 1-day first aid and CPR class, be doing field appendectomies (at least not on anyone you actually want to save). The absolute bare-bones minimum training you should pursue is basic certification as an EMT, emergency medical technician. (For reference, that’s 2 steps below a paramedic, 4 steps below a registered nurse, and 6 or more steps below a doctor). It’s also 140+ hours more time than a 1 day first aid and CPR class, and enough conveyed wisdom to turn you into a reasonably competent field medic with 20 times more training than 95% of the public at large. If you want, by all means go further, but don’t, in any event, think with less you’re ready to do much more than call 9-1-1, and even that last isn’t a dead certainty.

Having that training, you need the tools to do the job.

Second, a headlamp. Because invariably, you’ll need more light somewhere, and holding it robs you of a hand you’ll need elsewhere. Ditto for clamping a light in your teeth. Get a nice LED headlamp, and put it in the same pocket/pouch your exam gloves are in.

A wad of gauze 4x4s. I don’t care if they’re sterile, I do care if they’re clean. Stupidly, most companies package them in paper. Put 5-20 in a small ziplock baggie, and they’re now clean, and relatively waterproof.

Bactine, Betadine and double or triple antibiotic ointment. To clean and disinfect wounds.

OTC meds: small quantities of aspirin, acetaminophen (Tylenol), and ibuprofen (Advil/Motrin). All relieve pain, and all reduce fever. Aspirin thins blood (good for possible heart attacks, bad for forehead lacerations). All have indications (when you should use them) and contraindications (when to not use them.) Any allergy to a medicine is an absolute contraindication. They also have effects (what you want them to do) and side affects (what you may not want them to do, and should know about). Once again, this is serious stuff, and a 1-day class isn’t going to get it done. Next, some diphenhydramine (Benadryl), an antihistamine. Which cuts down on hives, rash, itching, and allergic reactions. Temporarily. Also an antacid (Tums, etc.), and an antidiarrheal like loperamide (Immodium) to help you stop when all you want to do is go. Pseudoephedrine (Sudafed) for runny noses and plugged sinuses. You could add a whole drugstore, but there’s not much benefit to be gained carrying tons of other stuff beyond that list.

If there are any medications you personally need, for asthma, high blood pressure, diabetes, gout, allergies, whatever, etc., there should be some of them in your emergency kit – separate from the common meds, and clearly labelled as your personal Rx meds. There should also be a copy of your insurance card, and a copy of your personal medical history and info, summarized on a 3×5” index card. Blood type (if you know it), medical history, including surgeries, diagnosed conditions, and the meds you take for those conditions*, and any allergies**. If there’s room for a doctor’s phone number and emergency contact phone number, you’ll save potential rescuers having to beat all that info out of you someday, particularly when you might not be up to the game of 20 questions they’d need to play, because perhaps you aren’t conscious. Repeat as necessary for all members of your family/party/tribe/outting/whathaveyou.

At this point, you have replicated in the space of 1 sandwich-sized baggie, everything the hospital ER will do for you right up until the doctor sees you.

So now it’s time for the next things you’ll need.

One or two nasopharangeal airways, and K-Y jelly. NP airways look like rubber trumpets, and after a squirt of K-Y, etc., go into one or both nostrils to help maintain an airway with minimal muss and fuss, or more complicated interventions on your part.

One or two adhesive chest seals (e.g. Asherman) – I prefer two on the theory that whatever made a hole going in may have made one going out, and you’ll need to seal both holes. More than two chest holes and your work is cut out for you. But a chest seal that prevents or stops tension pneumothorax (look it up) is way more fun that trying to fix one once it’s happened.

A large bore catheter/needle to solve the problem I just had you look up, in case it happened before you could deploy your sticky chest seals.

Blood-congealing gauze (Quick Clot, etc.) for large, profusely bleeding extra openings.

Israeli 4” and/or 6” pressure dressings, to seal and put pressure on the gauze dressing above that you just crammed into that gaping wound.

Ace wrap(s), to double up on the pressure on the dressing above, and also to treat ankle, knee, and wrist sprains. Carry several, e.g. 2″, 3″, 6″.

A CAT (combat application tourniquet) or 4 for temporary application, either because proper medical assistance is nearby, or to briefly impede/decrease the outflow of blood long enough to let wound elevation, pressure dressings, and blood clotting mechanisms kick in. Current medical reports from Iraq and A-stan are that field tourniquets to extremities applied for up to 6 hours demonstrate no or negligible complications or long-term effects. But if you need it more than 6 hours, you may be sacrificing a limb, and then probably they’re going to die anyway from gangrene and/or other infection within days if you have no access to definitive medical/surgical care.

More gauze 4x4s, or 2x2s, 3x3s.

Medical adhesive tape. Waterproof, silk, plastic, paper. Ideally 1 of each. Small scissors to cut it.

SAM folding aluminum splint roll.

Waterjel for burns. Moleskin or Secondskin for blisters. Sunscreen, lip balm, insect repellent. Quality splinter tweezers. All self-explanatory.

That’s it. If you want the bulk, you might add a stethoscope, BP cuff, and a thermometer. But most of what they’d tell you could be discerned without them, since they only expand your abililty to see, hear, and touch. So they’re ultimately optional. A CPR mask with one-way valve, for when 9-1-1 is within minutes. (Because when it’s not, though you do CPR or artificial respiration until you pass out, your patient likely isn’t going to make it.)

That kit will equip you to deal with minor to major trauma – punctures, lacerations, incisions, etc., fractures/sprains/dislocations, burns, blisters, sunburn, allergies, and countless minor medical problems/illness.

More mainly consists of more of the above, rather than endless numbers of new things.

What you really don’t need:

One of those small field instrument/minor surgery kits. Because as anything less than a duly licensed and properly trained physician’s assistant or doctor, you aren’t going to probe injuries, remove bullets, or sew up holes. Because you’re likely not going to tote around  a quart of betadine and sterile saline for each event , plus sterile field, drapes, and gloves, along with 20-30 varieties of sterile suture material at $15 apiece for every possible injury. Nor are you likely going to be able to properly clean such wounds sufficient for surgical repair, and come up with the necessary local anesthetic necessary to make the experience less than screaming torture for your patient. Nor a selection of antibiotics to make field wound closure of poorly cleaned wounds not result in a massive and possibly life- or limb-threatening infection for said patient. Do your best to clean and disinfect them with the other supplies, pack and wrap them, and monitor them regularly while changing dressings, yes. Try to be a 19^thcentury surgeon, and you can expect 19^th century mortality levels. So no. No matter how many pig’s feet you practiced on with bootleg suture material.

Note that this is for relatively short-term emergencies and predictably small events that you can and should anticipate. It isn’t a list for long-term scenarios nor to replicate/replace a hospital if such is available. The kit above, with your proper training to utilize its contents, will enable you to deal with about 80% of what you might face, and closer to 100% of what you might successfully address. In extreme circumstances, the other 20% are things which are going to happen, and some people you aren’t going to be able to save. You do the best you can with what you know and what you’ve got, and until your patient is obviously dead. Circumstances will dictate what happens after that, and it may not be pretty. Prepare for things accordingly.