7 Ways to Avoid Getting Sick When You Fly

If it seems like you pay for every plane trip with a bout of cold or flu, you're not far off. The best research published so far shows that airplane passengers are 113 times more likely to catch a cold during a flight than during normal daily life.

While recirculated air is most often blamed when people get ill after a flight, the researchers' conclusions were much more surprising. The prime culprits: Dry air and the body's physiological response to lack of humidity top the list, followed by "small cabin space per person," then limited air circulation. But instead of spending your time in transit worrying whether germs lurk in every corner, take steps to protect yourself. Here's a seven-step plan to arm yourself against cold and flu viruses while you're in transit.

Step 1: Stay well hydrated.

Most commercial planes fly at elevations between 30,000 and 35,000 feet, where humidity is well below the 15 percent required to keep nasal passages moist. When the mucus membranes of the nose and throat get dry, it inhibits the natural drainage system that carries any viruses or bacteria encountered down to the stomach to be flushed out. Drinking water keeps the mucus membranes in the nose and throat moist and better equipped to fight germs.

What helps: Drink a bottle of water before you get on the flight, so you start your journey well hydrated. If you hate buying bottled water, carry an empty water bottle through security and fill it as soon as you're through.

Step 2: Travel with nose protection.

According to the National Institutes of Health (NIH), airborne germs are one of the top-two sources of cold virus infection. You can't make sure the limited amount of air on a plane is germ-free, but you can try to prevent the germs from getting to you.

What helps: Use a saline nasal solution or nasal mist to keep your nasal passages moist (just follow the directions on the bottle), which effectively boosts your body's own germ-flushing action. Or try applying a small amount of Neosporin or petroleum jelly just inside the nostrils (use a Q-tip if your hands aren't freshly washed). Experts say the antibacterial action of Neosporin is unlikely to present much of a barrier when used in this way, but it never hurts to moisturize the inside of the nose.

The steam from hot drinks, like tea and hot chocolate, is also an effective way to keep the mucous membranes moist. (Skip the coffee, though, since it's dehydrating.) A great solution is to carry your own decaf or herbal tea bags and just ask for hot water.

Step 3: Be on guard against food-borne bacteria.

Although you may like the convenience of in-flight meals on shorter flights, those served on longer flights and in first class may not be the perk they appear to be. In 2010 the FDA issued a warning about food-borne illness from airplane food, reporting that cockroaches, ants, flies, and debris had been found during an inspection of the Denver facility of the world's largest airline caterer, LSG Sky Chefs, which provides 405 million meals a year worldwide for more than 300 airlines. The FDA also detected the deadly bacteria listeria in samples taken from a kitchen floor.

Since then, LSG Sky Chefs says it has taken measures to remedy the problems. But such information isn't exactly reassuring, and FDA inspection reports show that unsanitary and unsafe conditions have been found in many of the catering operations that have provided food to airlines in the last two years.

What helps: Since heat kills most food-borne bacteria, pay close attention to whether your airline meal is served piping hot. If you see evidence that a meal wasn't heated thoroughly, such as a still-frozen or cold spot in the center, send it back. Make sure all snacks and sandwiches are served in plastic. Better yet, bring your own food from home.