Colds, flu and similar viral infections produce more useless doctor visits than all other ailments combined.

Dr. Michael Oppenheim believes home remedies are best. In Better Homes and Gardens magazine he offered the following suggestions for treating such ailments at home:- For a fever, drink plenty of fluids and keep cool. A 102- or 103-degree fever will not damage a healthy body, so there's no need to "bring it down." Take acetaminophen, if desired. Calm a sore throat with a salt-water gargle; or use an over-the-counter spray or lozenge.

- Breathing in steam will relieve stuffiness and loosen a cough. Many medications do the same, but most contain antihistamines that may cause drowsiness. A few don't (Sudafed, Daycare).

- For a dry cough, use cough drops or hard candy. Or try an over-the-counter cough remedy with dextromethorphan.

- Always phone the doctor if the following symptoms occur:

-Any sore throat, fever and swollen glands without a cough or runny nose are typical of strep throat.

-Severe cough with fever, shakes and chills is a sign of pneumonia.

-Sinus infection causes severe pain over one sinus. Aching over the cheeks and forehead is sinus congestion.

Phone if ordinary cold symptoms last more than two weeks, sooner if symptoms get worse. Call immediately if the above symptoms occur.

- From Better Homes and Gardens, a Meredith magazine