Prevent congestion in a plane

The lack of humidity inside an airplane sucks moisture from the tissues of the nose and mouth, compromising the body's natural defense system. Stock your carry-on with a bottle of nasal saline spray, and use it before you fly to irrigate and moisturize the delicate membranes inside your nose. If you have a cold, take an oral decongestant about 30 minutes before boarding. If you have allergies, take your allergy medication an hour before flying.