Do
Become a hermit. The only foolproof way of escaping colds altogether is to avoid human contact. Second best: Stay away from children, the major reservoirs for cold viruses. A bit impractical? Read on.
Wash your hands and don’t touch your face. If you can adhere to these two rules, you could be well on your way to cold-free dreamland. The most common of cold viruses like to travel by way of nasal secretions—from the hand of an ill person to an object or to the hand of an unsuspecting recipient, who then “self-inoculates” by touching eyes or their nose. So you’re probably a lot more likely to get a cold from a simple handshake than you are from kissing or getting sneezed on. Distressing fact: In a recent survey, one in 10 Americans admitted to wiping their nose on their hand and then extending it for a doorknob or handshake.

Experts say that the best advice for dodging cold bugs, then, is to wash your hands often. You don’t have to be Lady Macbeth about this. Just wash up after events that involve a lot of hand contact, such as sports games or business meetings. Plain soap and water is best—it doesn’t inactivate viruses but mechanically dislodges them from your skin. Don’t bother with antibacterial soaps; they’re aimed at bacteria, not viruses.

As for not touching your face: Easier said than done. Just try it for a few hours. Studies show that most of us touch our faces hundreds of times a day—and that we pick our noses as much as five times an hour. These are hard habits to beat. But if you want to avoid a cold this season, start practicing now. I also rather like the suggestion that right-handed people train themselves to touch their eyes and nose only with their left hand, using a “clean hand” for this purpose and a “dirty hand” for contact with the surroundings.
Sleep long and hard. People who sleep fewer than seven hours a night are three times more likely to get colds than longer sleepers. And people who don’t sleep well are five times as likely to get a cold as deeper sleepers.
Exercise. Lace up the sneakers for 30 to 60 minutes a day of moderate exercise, and you’ll likely suffer fewer colds than people who don’t exercise, and also, fewer days of sickness from colds. Having a cold shouldn’t hamper your capacity for exercise—at least as long as it hasn’t settled in your chest. (Use the old "neck up" rule of thumb: Exercise only if you have no fever and your symptoms are limited to the neck up.)
As the old saying goes, if you treat a cold, it will last about seven days; if you don’t treat it, it will last about a week.
Be happy. Extroverts and people with a so-called positive emotional style are less likely to catch colds than their less-ebullient counterparts.
Be social. Though it may seem counterintuitive, people with diverse types of social relationships—through work, community, religion, sports, etc.—get fewer colds than those with limited social circles.
Don’t
Don’t worry about cold temperatures. You can’t catch a cold from catching a chill. Cold doesn’t cause colds; viruses do. And being chilly doesn’t make you more susceptible. Colds are more common in fall and winter because the colder, wetter weather drives people indoors, where viruses jump more easily from one nose to the next.
Don’t bother trying to ‘boost’ your immune system. Cold symptoms are caused not by the destructive effect of cold viruses themselves but by the body’s own immune response to the intruders. Our immune system makes inflammatory agents that inflame the cells and tissues of our nose and throat, causing all the annoying symptoms of a cold: the runny nose, cough, sneezing, etc. So boosting your immune system with herbs or supplements may be counterproductive because you may be boosting the very agents that cause your symptoms, aggravating them.
Don’t get stressed out. Try to avoid chronic stress—the kind of cumulative stress from long-term worry about work, debts, marital issues, illness in the family. People who are chronically stressed are more likely to come down with colds.
If you do get sick, don’t blow your nose too hard. Nose blowing doesn’t relieve stuffiness. A stuffy nose doesn’t result from too much mucus but rather, from the swelling of blood vessels in your turbinates—the spongy shelves lining the sidewalls of your nasal passages—which you don’t particularly want to expel. Also, forceful nose-blowing can drive nasal secretions into your sinuses, where they can cause secondary infections.
And don’t ask your doctor for antibiotics. Antibiotics are powerful drugs designed to kill bacteria. Colds are caused by viruses, so antibiotics have no effect on them. Moreover, the misuse of antibiotics can result in the development of strains of bacteria resistant to common drugs. (Still, antibiotics are inappropriately prescribed for colds at the staggering rate of more than 40 million prescriptions a year.) As the old saying goes, if you treat a cold, it will last about seven days; if you don’t treat it, it will last about a week.
Jennifer Ackerman's most recent book is Ah-Choo! The Uncommon Life of Your Common Cold (Twelve, 2010). Her previous books include Sex Sleep Eat Drink Dream: A Day in the Life of Your Body ; Chance in the House of Fate: A Natural History of Heredity ; and Notes From the Shore . She is also the co-author with Miriam Nelson of a book on women's health, Strong Women's Guide to Total Health (Rodale, 2010). A contributor to National Geographic and The New York Times, she is the recipient of an NEA Literature Fellowship in Nonfiction and a grant from the Alfred P. Sloan FoundationMore information can be found at her website: www.jenniferackerman.net