Every frequent flyer knows that flights are dehydrating, but why? This is what I’m contemplating on my 6 hour flight to Miami this morning. I’m stocked with my usual flight kit- large water, coconut lotion, lip balm, oatmeal, snacks, book and computer. Is there something else I should be doing? Thankfully there’s internet on the flight so my 3 hour google search has discovered the following gems for my fellow jetsetters: Why are flights so dehydrating? The air on an airplane is 3 times drier than the Sahara Desert! An aircraft’s filtration system—which takes in outside air and circulates it in the cabin—is to blame. Says Dr. Clayton T. Cowl, the chair of Aerospace Medicine at the Mayo Clinic, While this creates a clean environment, it also causes humidity to drop to a parched 10 to 20% between 30 and 65 % is comfortable for most people. Low humidity means that moisture evaporates from the body quickly, which leads to dehydration. How much water do we actually lose on a flight? LAX and NYC flight (5 hours) a woman loses about a quart of water. How do we keep our skin from drying out? “Typically, skin is comfortable when the humidity is between 40 to 70%,” says Melissa Kanchanapoomi Levin, a clinical instructor in dermatology at Mount Sinai Hospital in NYC. Look for items that contain hyaluronic acid, like SkinCeuticals serum. “When there is no water in the air, moisturizers don’t work as well since there is nothing to grab onto,” Hyaluronic acid—a sugar molecule found naturally in the skin—has an amazing ability to bind to water. Also: Skip the facial mist. It might feel refreshing, and you may think you're hydrating your skin by spritzing, but as the water evaporates from your skin, it can just make dryness worse. How do we fight water retention? Post-flight puffiness is a combo of inactivity and increased salt intake (airplane food = salt bomb). This shows up as facial puffiness, bloated stomach and an overall feeling of blah. Packing your own food and doing a post flight exercise is vital- even a brisk walk will help. A post flight workout + sauna is ideal. How much water should I drink on the flight? According to the Aerospace Medical Association, you should drink about eight ounces of water for every hour you’re in the air. Peter Hackett, M.D., director for Institute for Altitude Medicine told Condé Nast Traveler ‘this is especially the case if you’re on flights longer than three or four hours.’ Hydrating snacks are also helpful- organic fruits, vegetables, and coconut water. Its best to start hydrating the day before travel. Add turmeric and other anti inflammatory to your pre-flight meal. The Good News: Modern jets like the Boeing 787 bring the air in directly rather than through the engines which increase the humidity by 15-20%. Check your flights. Safe Travels!