Willow is good for pain relief, for the types of conditions that you can use aspirin for. Willow carries the same precautions and warnings that aspirin does. Children under 12 should never be given it. If you are allergic to aspirin you will react to willow.
When using tree parts as herbal remedies you use the inner bark, the slippery smooth part located just under the outer bark that is not attached to the wood of the tree. Fresh is more potent than dried but it can be dried for use later. Cut/chop when fresh to avoid the difficult task later. General rule of thumb, one tablespoon is approximately 1-250 mg tablet of aspirin. However keep in mind temperature, lack or abundance of water and growing conditions will affect potency. The wetter the less potent, dryer means more potent. Stress, (bugs, location etc) will also affect potency.
Raspberry, Blackberry and Catnip are used for cramping like gastrointestinal flu, colic, that sort of thing.
Skullcap and Valerian when used together (40 percent skullcap 60 percent Valerian) create a very potent pain reliever. Like most heavy pain killers this blend can be addictive and should not be used for more than 10 days without a 7 day break. Seeds for both are available.
Topical anti-bacterial/antiseptics include garlic, yarrow, oak (all kinds with white being the more potent) onion, garlic, lemon balm, tea tree (which only grows in your particular area) basil, and most citrus or high acid fruit juices.
Most of these are for topical use however basil, garlic, onion, yarrow, lemon balm and fruit juice can be used internally.
Unlike popular belief, echinacea (also available in seed)only stimulates the immune system helping it work more effectively.
Antivirals include lemon balm, black locust and oak. Black elderberry syrup (commercial name sambucol) is very helpful in upping up the immune system to speed up the recovery. It was used during the Spanish flu outbreak with better results than any other treatment. It can be made at home using dried or fresh berries with alcohol (for long term storage) or water to be used quickly.
Blackberry and raspberry are excellent to use for vomiting and diarrhea since the actions help prevent the contractions (spasms) that encourage vomiting/diarrhea.
Coughs respond well to horehound, cherry bark (keep in mind that when using any type of cherry bark it MUST be dried thoroughly first) and bergamot (the thing that makes Earl Gray tea Earl gray tea) Other herbs can be added including lemon balm, bergamot, catnip etc.
Sore throats can be made less painful by gargling with salt water (1 tablespoon to 1/4 cup water)and spit out. Honey shots (do not use honey on children under 3 years of age) which can include basil, lemon basil, yarrow, cherry or horehound allowed to steep in 2 tablespoons of Very hot water then stir in 1 teaspoon of honey. Gargle and swallow it all.
For flu-like symptoms take 2 medium onions, 1 bulb of garlic, peel chop into quarters add enough water to cover, boil until half the liquid remains. Gargle one teaspoon-tablespooon swallow. The mush can be added to broth for additional support.
Fevers can be treated by the use of cool cloths as well as onion, garlic, leek, tarragon, chrysanthemum, rose of sharon, mints, bergamot, most of the sorrels, cinqufoil, oak, willow (provided the person is over age 12 and not allergic to aspirin) sage, skullcap, and sage. Keep in mind that fevers are the bodies way of making the environment hostile for germs and viruses. High fevers however can become dangerous. While they are hard to come by, non-digital thermometers may be great to have in the first aid kit. Finding rechargeable batteries may be difficult especially the flat pancake type.
Above all else common sense is the best recommendation. Even small scratches and scrapes should be cleaned thoroughly, using hot water and soap (or ground herbs in the event that soap is unavailable) Take standard precautions to avoid catching whatever bug someone else has. Wash hands often, if necessary use a cloth or mask to avoid breathing in contaminated air.
Fungal issues, diaper rash/athletes foot and the like can only occur when areas that are affected stay moist damp and not exposed to the air. Most diaper rashes can be easily cured by allowing the child to go diaperless. Athletes foot can be remedied with powder no shoes or socks. Fungus also thrives in people with high sugar intakes including fruits. All mints, chrysanthemums, nasturtiums, tea tree, and radish can also make the skin pH intolerant for fungus.
The best thing to do in a primitive situation is to stay as well fed as possible, meaning eat a balanced diet high in vitamins and try to keep caloric intake at 1800 per day per adult-teen.
Good personal hygiene (while more difficult in a primitive situation) will go a long way to prevent issues that are easy to deal with now that would become more inconvenient to treat later.
When making herbal teas the not quite boiling water is added to the herbs in the container. The container is covered to keep the volatile oils in the fluid. A minimum of 10 minutes of steeping is recommended. Straining is not necessary and with the exception of some tree barks the entire mix can be swallowed for additional benefit.
Also remember many edible wild plants contain more vitamins and minerals than domesticated food plants. Plantain is one having more iron and C than spinach.