Wherever you go, practice the Big Three antiflu strategies.

RODALE NEWS, EMMAUS, PA—Swine flu is making its rounds around the country—including your neighborhood—and over the weekend, President Obama declared the situation a national emergency. "Just being out in the world means you'll encounter individuals who are shedding the virus," says William Schaffner, MD, president-elect of the National Foundation for Infectious Diseases and chair of the department of preventive medicine at the Vanderbilt Medical Center in Nashville. And you can't always tell who's infected. H1N1 is shed, "or excreted, to use a tackier term," says Dr. Schaffner, in its highest concentrations the day before an individual gets really sick, mostly by traveling on the droplets that are spewed when someone coughs or sneezes. The volume of shed virus begins to diminish thereafter, he says, but a person can still pass the germ along until 24 hours after symptoms disappear and his or her fever goes away. So if you're sick, it's important to stay home until symptoms improve. And if there's a serious outbreak in your community, you might want to consider cutting out trips that aren't really necessary. But if you know how to handle yourself at the grocery store, on the bus, or even at the World Series, you can do little things to lower your risk of catching H1N1 without turning into a complete hermit. (If you can get a flu shot, do that too.)

Even as H1N1 circulates, life goes on. Here are ways to lower your risk of catching the illness in common public settings:

#1: In movie theaters. The average big-screen movie theater has between 200 and 300 seats, and with today's megaplexes including as many as 26 theaters per venue, that could mean upwards of 8,000 people in one building on a crowded Saturday night, many of whom may be actively shedding the virus without knowing it. Strategy: Reschedule. First, ask yourself if seeing a blockbuster on opening night is worth the risk of H1N1. "During a season such as this, perhaps it's better to rent a movie rather than going to a theater," says Dr. Schaffner. Should you decide that you can't stand another minute at home, head to the theater when you know crowds will be lightest. At the very least, you can maintain the optimum three to six feet—that’s the distance needed to prevent swine-flu transmission—between you and other potentially sick moviegoers. And wash your hands for a full 15 seconds when you head to the bathroom, or take a hand sanitizer with you. Most people avoid or minimize hand washing in the rush to return to their seats so they don't miss anything.