A tickle in your throat. A cloudy head. An achy body. Yep, you're coming down with something. Again. The average adult gets three colds per year, each lasting an average of nine days, says Jane Sadler, M.D., a family practice physician at Baylor-Garland Hospital in Garland, Texas. But you don't have to surrender. Here's how to stop a cold before it takes hold -- and feel better by tomorrow.