Fasten your seatbelts and take your echinacea: don't let your summer vacation be ruined by sickness, jet lag and queasiness. Pack your bag to fight the germ-friendly skies

Set aside the inconvenience of air travel--tight security, smaller seats and bad food--and any flight attendant will tell you that traveling isn't very good for your health. The dry air, the prolonged sitting and the stress caused by losing your luggage or having a flight cancelled can take a toll on your immune system. In addition, when you get there, jet lag chips away at your senses, leaving you tired and susceptible to illnesses you never dreamed of. "We didn't evolve to fly," says Hyla Cass, MD, chair of complementary and alternative medicine at the American University of Complementary Medicine in Los Angeles and co-author of Natural Highs: Feel Good All the Time. You have to do everything you can to take care of yourself because our bodies weren't built to travel through time and space at the startling speed that airplanes do.

before your trip

So what can you do to stave off fatigue, germs and parasites? (Sorry, not the guy in the seat next to you--that's another story.) The first countermeasure is to be healthy before you travel. If you're heading far off the beaten path, it's best to start thinking about travel-related health issues at least six weeks before you leave, says Isabelle Young, author of the Lonely Planet Healthy Travel book series. Make an appointment, and tell your healthcare provider where you're going, how long you plan to stay and if there have been any changes in your health since your last visit.

Depending on exactly where you're headed, immunizations may be in order. If you prefer to avoid conventional vaccinations, "You could boost protection with homeopathic immunizations for a week or so," Young says, "but bear in mind that their effectiveness has not been fully studied." They may work for minor illnesses, but they aren't recommended for people with immune-system problems or for pregnant women.

stress-proof your body

While you're packing for your trip, remember that, despite what the flight attendant may be required to say, the plane is designed for maximum seating capacity--not your comfort. Bring things to stress-proof yourself. "Our bodies are like little children when traveling," Cass says. "They need the basics: sleep, good food and hydration."

Sleep can be difficult to come by when traveling. Alcohol may seem like a good way to de-tense, but it's de-hydrating. Cass recommends talking with your healthcare provider about herbs such as GABA, valerian and kava to make the flight more relaxing. (If you have liver problems, talk to your healthcare pro before taking kava. Also, don't mix alcohol with stress-relieving supplements.) Consider packing supplements that work for more than one purpose, says Pamela Hirsch, author of The Traveler's Natural Medicine Kit. "Chamomile tea keeps me calm, but it also works for nausea and as an anti-inflammatory."

When traveling across time zones, the body's circadian rhythms, which respond to day and night, get confused, causing fatigue, sleep problems, queasiness and trouble concentrating--otherwise known as jet lag. To reset your body's clock, try staying awake until a reasonable hour on the day you arrive, and then get a full night's rest. If you can't fall asleep, try melatonin. While controversial for a while, the latest research shows that the supplement does help fight off jet lag. Cass suggests taking 1-3 mg of melatonin about an hour before you want to fall asleep, but no more because larger doses can have a hangover-like effect. Another popular supplement is a homeopathic remedy called No Jet-Lag, available at natural products stores.

Your digestive system may backfire as a result of the tension or motion sickness that travel brings. Carry a selection of supplements such as ginger, enteric peppermint, bitters, lactobacillus tablets or a homeopathic remedy called Trip Ease for nausea and intestinal problems. Hirsch likes to inhale peppermint oil for fast relief from nausea, but because of increased security, a bottle of clear liquid may attract attention. Instead, Hirsch suggests saturating a handkerchief or tissue with the oil and storing it in a sealed plastic bag.

For motion sickness, wristbands that target acupressure stress points may settle your stomach and are particularly useful for pregnant women with already sensitive tummies. But just buying the wristbands and putting them on is not enough. Make sure someone knowledgeable shows you exactly where the bands should be worn. If they're not putting pressure on the right spot, they're useless.

Hydrating your skin and body is one of the easiest and most important things you can do. Mist your face with water, then apply lotion to hold in the moisture, and try to drink at least one glass of water every hour that you're flying.

Along with water, immune-enhancing supplements such as echinacea, goldenseal and vitamin C will help fight off any germs floating through the cabin. Cass says that it's not a bad idea to begin taking these supplements the week before you leave. Hirsch tucks a supply of them in her carry-on luggage as well as bottled water mixed with Alacer's Emer'gen-C for hydration and immunity.