Water is good for everyone, right? Not quite. Doctors at John Hopkins Children Center are spreading the word that for babies under six months, water can be dangerous. That's because these tiniest kiddos have a strong instinct to drink. They can take in too much water, which leads to water intoxication. This affects sodium levels in the body, which can lead to mental changes, puffiness, low body temperature, and seizures.

With summer's heat on its way, it may be tempting to give your young infant water. But experts urge parents to stick with breastmilk or formula instead. Older babies can have small amounts of water, but doctors still say to stick to one to two ounces at a time and to check with your doctor first.

For tips on how to keep your baby cool this summer, check out the gallery below.