Water Continued...

You’ll Be Less Apt to Get Sick...

Why: Hydration keeps your mucus membranes in top working order -- they're gatekeepers to the natural defense system that helps keep out germs such as cold and flu viruses. When these tissues dry out, germs can more easily penetrate to the nasopharynx, where the nasal passages and mouth meet. And if you catch a bug anyway, the severity of your illness is more likely to be lower if you've been drinking a lot of water.

Water is an especially smart health move when you are traveling. Most commercial planes fly at elevations between 30,000 and 35,000 feet, where humidity is 10 percent or lower. That means you're breathing dry air in a tight space filled with germs from dozens of people. Water keeps your mucus membranes moist -- and your defenses high -- even in that challenging situation.

Water-drinking tip: Bring an empty water bottle with you to the airport that you can fill for free once you're past security. Or buy the biggest bottle you can right before you board, and aim to finish it by flight's end. Don't hesitate to ask the flight attendant for refills while you're in the air.