“I wash my hands all the time and open doors and touch elevator buttons with a clean tissue whenever possible,” says Dan Collins, who works in media relations at a Baltimore hospital. “When I return to my desk, I immediately grab my supply of antibacterial hand wipes. And whenever my eye itches, I never use the tip of my finger to scratch unless I can sanitise my finger first; instead, I use my knuckle or the back of my hand, as these areas have had less contact with germs than my fingertips.” Collins also holds his breath “for a good 15 seconds” if he walks by someone who sneezes, and he takes zinc at the first sign that a cold is trying to take hold (usually a telltale back-of-the-throat tickle)—a habit that research supports.

Regular exercise strengthens the immune system and makes you less likely to catch upper respiratory infections, according to a study in the Journal of Sport and Health Science. “My husband and I work out at least three times a week, and we’ve been working with a personal trainer for a number of years,” says Julie Michener, from Minneapolis. “I think that’s why I don’t get sick even when everyone else in my office does.”