Planes, trains, boats, and automobiles can quickly turn into roving torture chambers when motion sickness kicks in. Some folks are more susceptible than others, but most travelers get hit with it sooner or later. Here's what to bring along when you take to the road this summer, so you can enjoy your lunch-and avoid losing it.

First, the one piece of good news about motion sickness: If you're traveling with infants, you probably won't have to worry about them. Children rarely get motion sickness before age 2. But as kids grow up they become increasingly susceptible. The worst years are usually between the ages of 4 and 10. Women are more often affected than men, especially when they are pregnant, menstruating, or taking birth-control pills. Also, migraine sufferers appear to be more prone to motion sickness.

So what causes that queasy feeling? "Motion sickness is often a disconnect between what the eyes see and the body feels," says Paul Gahlinger, M.D., adjunct professor of medicine at the University of Utah in Salt Lake City and a pilot. You get seasick below deck in a boat because the appearance that nothing is moving doesn't jibe with the sensation of motion felt by your inner ear. "One way to right yourself is to focus on a visible horizon," says Gahlinger. Go on deck and focus on the point where waves meet sky; in a car, look at passing scenery. "If you can't do that, minimize the brain disconnect by lying down or reclining and closing your eyes."

This article first appeared in the July 2008 issue of ShopSmart.