The number of emergency room visits caused by children ingesting batteries has more than doubled in recent years, according to a new study published in the journal Pediatrics. Researchers with Safe Kids Worldwide found that most of these injuries occurred in patients 5 years old or younger. In 85 percent of the cases, button batteries were involved. These are small, disk-shaped batteries often used in remote controls, key fobs, and many children’s toys. Batteries are harmful once swallowed because they generate a harsh, corrosive substance that can cause serious injury and illness if it erodes into certain organs. Parents should keep an eye on any items with these types of batteries in their homes, not just kids’ toys.