Achoo!

Unless your holiday wishes include a vacation to the emergency room, you may want to watch what you touch on the subway—and whom you stand next to.

Dr. Bruce Polsky, who serves as chairman of the Department of Medicine at St. Luke’s Roosevelt Hospital, says that although unlikely, tuberculosis may be lurking on your next C train.

Not to worry though, he's got some tips to keep your cough at bay.

"Every time someone coughs or sneezes, they generate an aerosol droplet of fluid that can contain infectious microorganisms, particularly viruses like influenza," the doctor told NYMag.

"And the Centers for Disease Control is labeling this a potentially bad flu season in terms of the amount of cases we might expect."

Dr. Polsky said that the flu claimed the lives of six children nationwide this year. Children, pregnant women and seniors are in the most danger, the doctor said.

New York is one of eighteen states that have announced “widespread” flu expansion, according to the Centers for Disease Control, resulting in more cases than previously recorded.

If you're afraid of needles, not to worry, vaccinations aren't the only way to stay healthy in 2013.

Dr. Polsky says that a touch of “respiratory etiquette” can go a long way underground.

For example, don't sneeze into the face of the straphanger standing in front of you— try the crook of your arm instead.

Another tip would be not to touch anything. At all. Ever. According to Dr. Polsky, germs can live for several hours on metal poles and other durable surfaces.

You may also want to cover your nose and mouth if someone else is coughing in your vicinity, giving them the stink eye before they give everyone pink eye.

If you want to get stared at like a crazy person, you can go the extra mile and wear a surgical mask a la the 2002 SARS epidemic.

Other strategies include washing your hands before touching your mouth or nose and, the doctor recommends, moving away from the schlub on the subway who is sneezing all over you.