Kids like to drink something with meals and should definitely drink water when they are thirsty. When it's warm out or you're exercising, you'll need more fluids. Be sure to drink some extra water when you're out in warm weather, especially while playing sports or exercising.
Water is needed by all the cells and organs in the body in order for them to function properly. Without water, your body would stop working properly. Water makes up more than half of your body weight, and a person can't survive for more than a few days without it.
Your body doesn't get water only from drinking water. Any fluid you drink will contain water, but water and milk are the best choices. Lots of foods contain water, too. Fruit contains quite a bit of water, which you could probably tell if you've ever bitten into a peach or plum and felt the juices dripping down your chin! Vegetables, too, contain a lot of water — think of slicing into a fat tomato from the garden or crunching into a crisp stalk of celery.