Children's Hospital of Pittsburgh says parents need to be wary of small, disc-shaped button batteries in toys, household electronics, including watches cameras and games, and even in singing or flashing greeting cards.
The batteries may look like candy to a child, but if swallowed, the battery may stick in the throat or stomach, causing life-threatening burns and tissue damage as the chemicals leak out. Severe burns can occur in as little as two hours after swallowing.
If you suspect your child has swallowed a button battery, seek immediate medical attention even before symptoms appear. Symptoms may include coughing, drooling, trouble swallowing and fever.