The next time you slide behind the wheel of your car, think about this: Driving is probably the most complicated thing you will ever do - unless you learn to fly. That's according to Dr. Dennis Doverspike, a psychologist at the University of Akron, in Ohio. He also says that using a cell phone while you're driving makes you 20 times more likely to crash. In a recent study, drivers using cell phones while driving took their eyes off the road for five seconds at time, literally driving the length of a football field at 55 miles per hour without looking. So, why do so many people multi-task while they drive? Because they drive so often it's become automatic, so they figure they can safely do more than one thing. Just one accident could instantly change your mind. Let me describe exactly what happens to your body during a car crash: First, when your car suddenly stops, your body - including your head - continues to move at the speed you were driving until it hits something - like the steering wheel, windshield or dashboard. On impact, your brain crashes against the inside of your skull, and then rebounds and smacks into the other side of your skull. At minimum, you have a headache or a concussion. At worst: brain swelling and death. Then there's your neck: The weight of your head whipping back and forth can cause whiplash, but if it's a high-speed crash, the motion could break your neck. Another thing that happens during a car crash: If your heart swings too violently into the back of your breastbone, it can tear off the aorta - the largest artery in the body, and you'll bleed to death. It's similar to the injury that killed actor John Ritter. Then there are your lungs. A lot of people gasp just before impact. Filling their lungs, and making lung ruptures more likely.* Finally, if there's enough force to drive the front end of your car into your knees, your thighbones will snap. Hopefully that description will stop you from even thinking about multi-tasking behind the wheel.