The air you breathe in the plane cabin actually comes from outside, and air at that altitude has very little moisture. “This air is very dry, having a humidity of under 10 percent,” says Quay Snyder, MD, MSPH, president and CEO of Aviation Medicine Advisory Service. “Dehydration can lead to a feeling of fatigue, particularly when combined with the lowered pressure of cabin air. Medical conditions and some medications may exacerbate these sensations.” The best way to prevent dehydration is to drink lots of water, even before you board the plane. Bring your own water bottle so you don’t have to rely on the flight attendants to get it for you.
