Travel Tips Why Do I Get So Dehydrated When I Fly? By Travel + Leisure Editors Travel + Leisure Editors Since 1971, Travel + Leisure editors have followed one mission: to inform, inspire, and guide travelers to have deeper, more meaningful experiences. T+L's editors have traveled to countries all over the world, having flown, sailed, road tripped, and taken the train countless miles. They've visited small towns and big cities, hidden gems and popular destinations, beaches and mountains, and everything in between. With a breadth of knowledge about destinations around the globe, air travel, cruises, hotels, food and drinks, outdoor adventure, and more, they are able to take their real-world experience and provide readers with tried-and-tested trip ideas, in-depth intel, and inspiration at every point of a journey. Travel + Leisure Editorial Guidelines Published on May 14, 2015 Share Tweet Pin Email Photo: iStockphoto Dry throat and itchy eyes—we’ve all felt the effects of flying. According to Dr. Clayton T. Cowl, the chair of Preventive, Occupational, and Aerospace Medicine at the Mayo Clinic, an aircraft’s filtration system—which takes in outside air and circulates it in the cabin—is to blame. While this creates a clean environment, it also causes humidity to drop to a parched 10 to 20 percent—between 30 and 65 percent is comfortable for most people. Low humidity means that moisture evaporates from the body quickly, which can lead to dehydration. Plus, when air is dry, the throat’s broomlike cilia become less effective at sweeping out viruses and bacteria, so you may be more susceptible to illness. The final word: There are ways to combat low humidity besides drinking water. Avoid alcohol- based moisturizers, which can be drying (Cowl recommends a vitamin E lotion); pack natural eyedrops and saline nasal spray; and skip the wine and cocktails. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit