This used to be called the medicine chest or the medicine cabinet. It usually meant the one in the bathroom. The one in the bathroom is good for keeping things like razors, shampoo, shaving lotion, soap, toothpaste and false eyelashes.

But not medicines.

It is the last place to keep medicines, most of which suffer serious deterioration from repeated exposure to light and warm moist air, the sort that fills the bathroom every time somebody takes a bath or a shower.

So first find a place that is:

*Safe from children. Preferably out of sight and out of reach of curious children, who tend to explore with their mouths as much as their eyes and hands. Even behind lock and key, if nothing else works. Remember, it's not just your own kids, either -- their friends may not be as well trained as yours. And don't forget about visiting grandchildren, who may think those pretty pink pills are candy.

*Relatively dark, cool and dry. Not, for example, near a heating duct.

Some things that go in a home medical center have special requirements. The aloe vera plant, for example, should obviously be placed where it can get appropriate sunshine; tweezers or thermometers should be kept wherever they are convenient. But pills, capsules, liquids, creams and ointments can spoil or lose their effectiveness when improperly stored.

When you stock your medicine center, pay scrupulous attention to expiration dates on all medicines. Some of them merely lose their effectiveness, but others, such as tetracycline, for example, can become toxic.

Remember, pregnant women should take no medicines, even apparently benign over-the-counter ones, without the specific advance approval of their doctors. The placental "barrier" is more myth than fact, and a developing fetus is the most sensitive of beings.

In general, most people should avoid any kind of medication whenever possible. Many cough syrups contain alcohol, which may be harmful to young children and may even make them drunk in some cases. Instead, try chicken soup, which has genuine therapeutic value for lessening chest congestion and coughs from colds. Asthmatic children should especially avoid cough syrups. Try sitting in the bathroom (not in the shower, though) with the hot water going in the shower to create an instant steam bath.

More and more researchers and physicians are finding that fevers may have a healing function and need not, perhaps ought not, be automatically lowered with aspirin.

The pains and aches from low to moderate fevers may be eased by tepid baths or, occasionally, alcohol rubs. In any case, fevers in children and high fevers in anybody should be reported to a doctor before self-medication is attempted.

The following are the suggested contents of a basic home medical center, according to Dr. Carole Horn, some of her colleagues and an occasional old wife:

*Syrup of ipecac. This is a potent emetic. Its sole purpose is to induce vomiting, and it can be life-saving when a child has swallowed some sorts of poisons or pills. Never use it, however, unless you check with a poison control center or emergency room first. Some poisons, such as lye, are caustic and may do as much or more damage coming up as they did going down.

*The aloe vera plant. The juice from its leaves is soothing. "I agree it's folklore," Horn says, "but it works."

*Aspirin. Tried and true pain reliever, and can even help you get to sleep. Never use it for a child who has flu-like symptoms or chicken pox. It has been statistically linked to Reye syndrome, a potentially fatal childhood ailment. Should be avoided by patients on anticlotting medications or with ulcers, since it can cause gastric bleeding in some people. Evidence is mounting that small daily doses can prevent or reduce the severity of strokes.

*Acetaminophen. The active ingredient in Tylenol or Datril. Has some of the qualities of aspirin, but less useful for inflammations. Overdoses in children can cause fatal liver problems unless an antidote is administered promptly. (By the time symptoms such as jaundice show up, it may be too late.) Excellent substitute for aspirin in children or people who can't take aspirin, however.

*Ibuprofin. A strong anti-inflammatory and antipain medication newly approved for over-the-counter sale. Sold as Advil or Nuprin. Excellent for post-surgical tooth problems, menstrual cramps, sprains. Should be avoided by anyone who is sensitive or allergic to aspirin. Sometimes causes stomach irritation.

*Bottle of hydrogen peroxide solution. For cuts and scrapes.

*Bottle of isopropyl alcohol. For anything that needs cleansing, or for rubs or cleansing tick bites. A few drops of alcohol in the ears after swimming can help prevent swimmer's ear and other infections from water-loving bacteria and fungi. (Not for use in perforated eardrums.) May be mixed with white vinegar if the alcohol alone seems too strong. (Also good for preventing mites in dogs' ears.)

*Antihistamine, such as Chlor-Trimeton or Benadryl. May cause sleepiness in pill form. Antihistamine ointment like PBZ is useful in temporarily relieving the itch or burn of minor insect bites and stings.

*Decongestant, such as Sudafed.

*Colace, a stool softener. Not for use in children without a doctor's approval.

*Pepto Bismol, an anti-diarrheal. Most diarrheas are self-limiting -- they go away without treatment -- and probably should be "toughed out" whenever possible. Pepto Bismol, however, is soothing in an occasional bout of gastric distress. Chronic diarrhea may suggest the presence of a parasite or other intestinal problem. See a doctor. If a fever is present with gastric pain, see at doctor at once. It might be appendicitis.

*Neosporin ointment. This is a mild antibiotic ointment that is, frankly, dismissed by some as useless. However, many doctors find it helpful in a variety of minor ills -- blisters, bites, scrapes and little cuts.

*A fever thermometer. And a backup -- they have a tendency to slip and break when you need them most.

*Bandages. Band-Aids, sterile bandages, Telfa nonstick pads. An ace bandage for sprains and strains.

*Diagnostic Implements. A pair of tweezers and a magnifying glass -- for splinters and ticks, or even porcupine or sea urchin spikes. The magnifier is useful in reading the thermometer, too. Heating pad. A comforting and possibly even therapeutic aid to aching bones and stiff necks.

*Vaporizer. A comforting and possibly even therapeutic aid to chest congestion from colds or minor respiratory problems. (Be sure it is placed so it they cannot be accidently knocked over, tripped over or bumped into.) There are new models that make vapor without heat, and they are safer but more expensive.

For people with special problems, such as hypertension or diabetes, there are a myriad of moderate to very expensive devices such as digital blood pressure readers and digital blood-sugar gauges. Check with your doctor before investing hundreds of dollars into elaborate equipment when simple and inexpensive kits may be available.

People who get hives or swellings, itching and occasional breathing problems from insect bites or stings could be at risk for anaphylactic shock -- a potentially fatal condition. Bee sting kits are available (by prescription) which administer an appropriate stimulant with the slap of a built-in syringe gainst the hip. This will usually hold a victim until emergency medical attention is obtained.

Under the best of circumstances, medicines, even aspirin, spoil eventually. Any medicines and ointments without specific expiration dates should be replaced, probably at least once a year. Do not save prescriptions left over from an old ailment. Always keep medicines in the bottles they come in so that you don't take one thinking you're taking another.

Keep the number of the local poison control center handy: The number for the National Capital Poison Control Center (at the Georgetown University Medical Center) is: 625-3333.