Understand why you’re carsick. Motion sickness happens when the brain gets conflicting signals from your inner ears, eyes, joints, and muscles. The inner ears and the skin receptors sense that you’re moving, but if you are reading or have your eyes fixed on an object in the car, your eyes can’t detect that the car is moving. One of the main symptoms is nausea, says Gervais Fréchette, M.D., a travel-medicine specialist in New York City and San Francisco.

Counteract nausea by looking outside. Says Fréchette, “Look at the horizon or the distant scenery,” which helps your body send the proper messages to your brain. Get kids to do the same by playing car games, like the license-plate game or I Spy. And, says Fréchette, “position a car seat so that the child can see outside.” Avoid caffeine, nicotine, and sodium. All three can impair circulation, interfering with the body’s ability to sense movement.

Ask your doctor about medications. She may suggest Dramamine, Bonine, or Marezine. But skip the wristbands and electronic devices that are claimed to prevent motion sickness. “There’s no scientific data to support them,” says Fréchette.