Inhaling hot, steamy air to treat a cold will not make it better and may even make it worse, according to a new study by pediatricians at the Cleveland Clinic.

In the study, published in today's issue of the Journal of the American Medical Association (JAMA), 32 cold-sufferers ranging in age from 14 to 60 inhaled heated, humidified air through their noses for 20 minutes. Each person received two such treatments, 60 to 90 minutes apart. A second group of 34 people with colds received "placebo" treatments in which they inhaled dry, room-temperature air. Then researchers recorded the cold symptoms of both groups for a week.

The placebo group got better faster. By the third day of the cold, 40 percent of the placebo group, but only 25 percent of the humidified-air group, reported a significant improvement in their sneezing, congestion and runny noses. By the seventh day, everyone in the placebo group, but only two-thirds of those in the humdifier group, had improved significantly.

In contrast to some previous studies that concluded that hot, moist air relieves cold symptoms, the new study suggests it may actually slow recovery by damaging the nasal lining. The authors offered several possible reasons for the conflict between their results and those of previous researchers, including variations in the temperature of the hot air tested in different studies, and differences in the heat-sensitivity of various strains of cold viruses.