Getting sick while traveling is a real bummer. And not just because you have to miss out on a vacation you meticulously planned months in advance. Falling ill while on the road can also cost you thousands of dollars if severe symptoms force you to seek medical care outside of your insurance network.To ensure a healthy travel experience, first be sure that you're not showing any symptoms of illness before you depart. If you are, do not board your flight. The stress, lack of sleep and physical stress you'll encounter while on the road will only amplify any pre-existing ailments you may or may not be battling. Assuming you're starting your travels feeling healthy, here are some simple tips to ensure that you do not get sick on vacation.\r\n\r\nBoost your immunityNasal mists and vitamin C tablets are your carry-on essentials. The airplane cabin is dry and microorganisms are free to circulate, so before you even step on the plane, take a couple of vitamin C tablets to give your body the ability to fight off airborne germs. Should the passenger sitting next to you start sneezing or coughing, you can easily take a few more vitamins. Saline solution and nasal mists are also effective in fighting germs, as they keep your nasal passages moist, which enhances your body's own germ-flushing activity. Some naturopaths also suggest applying a small amount of Neosporin or petroleum jelly just inside the nostrils (if your hands aren't freshly washed, use a Q-tip) to create a barrier between you and the airborne germs.Stay hydratedEven if you consistently drink water at home, it's easy to fall out of your normal routine on the road. But staying hydrated while traveling can be your biggest defense against germs. On top of the new climate conditions, you'll likely be more active than you are at home. So before you leave for excursions, kayak trips and tours, drink a bottle of water, pack two bottles with you for the day, consume a full bottle at lunch, and when you return... drink some more.Only drink filtered waterYou've likely heard scary tales of travelers getting sick from drinking tap water while overseas, but what you may not know is that it's not necessarily because the water is contaminated. The primary reason is that there are local bacteria that your body is not used to. (For this reason, foreigners who travel to the U.S. and consume the tap water often get sick as well.) Stay healthy by only drinking from sealed bottles or cans, which are sufficiently filtered. The local tap water is fine to shower with, but keep a bottle by the sink to brush your teeth. And if you can, avoid getting ice in your drinks.If you don't want to use a sufficient amount of your vacation budget on water bottles, consider buying a reusuable water bottle that's equipped with a filter, such as the water bobble or ZeroWater. And if you're a frequent traveler, you may want to invest in a SteriPEN, an ultraviolet water purifier that works on almost every kind of water in about two minutes.For more information about food and beverage safety while traveling, consider downloading the free Can I Eat This? smartphone app from the Centers for Disease Control and Prevention.Always pack motion sickness pillsIf you get lightheaded as a car passenger, there's a good chance that you'll feel a little woozy on a long-haul flight. To avoid sitting on the bench when there's an opportunity to take a boating or ziplining excursion, always have a supply of motion sickness pills. Just as important: be strategic about when you take them. Taking the pills too soon will make you drowsy, while taking them too late will make it harder for your body to recover. Pop them just a few moments before you fly, ride on a winding road or hop on a boat. Become a germaphobeWhen traveling, you'll share a lot of public spaces and possibly shake many hands, so be conscious about touching your eyes, nose and mouth. There's no substitute for hand-washing, but that's not always an option when on the road. Carry an alcohol-based hand sanitizer for those times when you can't get to the bathroom.And since you went to the trouble of packing disinfecting wipes or sprays, don't hold back in using them. Feel free to wipe down the airplane seat, armrest, touch screen or table; it's your space for the next few hours.You'll also want to bring your own blanket. Some airlines may offer you one, especially on long-haul flights, but if the blanket isn't wrapped in plastic that means it was used by someone on the previous flight. Your imagination can take it from there as to what the person before you could have done with it.