Wherever there are crowds, such as at football games, conventions, or music concerts, there are germs. Mayo Clinic infectious diseases expert Dr. Gregory Poland tells how you can avoid illness when you’re in a large throng of people, even in subways and on airplanes.

Whenever you’re in a venue with hundreds or thousands of people gathering, you automatically run increased risk for getting “something.” The people around you may not have the same immunization programs or the same standards of personal cleanliness or food safety, he said, especially if you’re in an international group.

Besides illnesses such as whooping cough, measles, mumps, colds and flu, other heightened dangers in places with large numbers of people passing through include respiratory diseases such as tuberculosis; vermin such as head lice and bedbugs; food-borne sickness such as E. coli, salmonella, hepatitis A and traveler’s diarrhea; and skin conditions including athlete’s foot and staph infections.

Dr. Poland offers these tips for sidestepping illness:

•  Keep your vaccines up to date: The most important ones include the MMR vaccine for measles, mumps and rubella; the seasonal flu shot; and a relatively new vaccine called Tdap, for tetanus, diphtheria, and whooping cough.

•  Wash your hands thoroughly with soap and hot water or an alcohol-based hand sanitizer.

•  Dine carefully: If it’s not cooked well, boiled or peeled, forget it. Make sure food that is supposed to be hot is served hot and food that is supposed to be cold is served cold, and make sure dishes and utensils are clean.

•  Wear shower/pool shoes when using the shower or pool in public places.

•  Avoid swimming pools, hot tubs, or whirlpools unless you are certain they are properly maintained, and it’s hard to tell.

•  Don’t smoke: It raises the odds you’ll get Legionnaires’ disease if you’re exposed to the legionella bacteria and can also make you more susceptible to respiratory illnesses in general.

•  Don’t try on hats in stores to minimize the risk of getting head lice. If you buy a hat, seal it in a plastic bag to carry it home, then freeze it for several days or launder it before wearing.

•  Scout for bedbugs in a hotel room, and once in a room, only place your luggage on wooden surfaces or in the bathtub, not on the floor, bed, chair or couch until you determine whether bedbugs are present.

•  Be an advocate for your health: If someone near you is obviously ill, move away if you can, or ask to be reseated.