Hard work, late nights, and the imminent election season, which unhappily coincides with the start of flu season, make a potent recipe for political candidates and staffers to catch a flu bug.
But it is the bread and butter of a political campaign -- connecting with people -- that truly puts a person like Sen. Barack Obama or Sen. John McCain at risk for illness.
"They are encountering so many people in such close quarters, often in enclosed spaces, for prolonged periods of time," said Dr. William Schaffner, chair of the Department of Preventative Medicine at Vanderbilt Medical School. "Getting close to people and shaking hands are risk factors for getting an infection."
Despite the cramped quarters during a presidential campaign that makes illnesses hard to avoid, experts say there are a few things candidates can do to stay flu-free as they work their way through election season.
The common admonition, Schaffner said, is to avoid those who are coughing, sneezing, have runny noses, and generally look ill. Three feet is all it takes for a healthy person to be able to inhale virus-laden water droplets spewed from the mouth or nose of an infected person.
But it is impossible to predict who will become ill or who has been ill recently. Influenza can be transmitted one day before and up to five days after being sick. Each year, 5 percent to 20 percent of the U.S. population gets the flu, according to the Centers for Disease Control and Prevention.
And political candidates get around. On the average day, Sunlen Miller, an ABC News producer covering the Obama campaign, estimated that Obama shakes hands with about 500 people.
"If I were in the campaign... just assume that I am encountering viruses all the time," Schaffner said.
And it is nearly impossible for a contingent of assistants and press to avoid a virus while traveling together.
"We're packed in the back of the plane like sardines," Miller said. "People pass on these sicknesses."
Avoidance aside, frequent hand-washing is an effective way to get rid of germs and viruses before they are transmitted to the nose or mouth.
Good etiquette, such as working in a sequestered area and using a tissue or a handkerchief or the crook of the elbow to block a cough or a sneeze, can also prevent flu from spreading.
"Bend your head away from everyone else, raise your arm, and sneeze or cough into the crook of your elbow," Schaffner said. "Do not spray your respiratory secretions into the vicinity."
Among the controversies that dot the campaign trail, doctors say using natural cold and flu remedies, such as Echinacea or Vitamin C, is one of them.
"We're rather pessimistic about both of them because the data are decidedly mixed," Schaffner said. "The impact at best is going to be small, though you might wish to use them regardless."
And Schaffner cautions that those who choose to take large amounts of vitamin C should drink two extra glasses of water so that the excess vitamin can be excreted through urine, preventing it from crystallizing in the urinary tract.
Staying hydrated, rested, and getting some exercise will keep you feeling well in general, Schaffner said, and better positioned to fight off an infection.
Most candidates do make a point to work physical activity into their schedules.