Photo: The Voorhes

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Spray Away Germs
The Sahara-like air on planes may spell trouble for your immune system. Dry nasal membranes are very susceptible to germs, says Martin L. Hopp, MD, PhD, medical director at the Cedars-Sinai Sinus Center in Los Angeles. "The cells lining your nose have microscopic hairs that move germs along," he says. "But if your nose is too dry, the hairs don't work efficiently." An hour before your flight, use a saline nasal spray or gel (rubbed around your nostrils and under your nose with a cotton swab), then follow up once an hour until you land. This helps prevent germs from making their way into your throat and lungs, where they can cause infection.