These small, coin-shaped batteries can be found in remote controls, thermometers, watches, calculators, hearing aids, flashlights, toys and singing greeting cards. They might not seem like a choking hazard at first, but these batteries can become lodged in a child’s upper airway once ingested and cause serious tissue damage in as little as two hours. They can also become easily lodged in a child’s ears and nostrils. Lithium-containing button batteries still have a strong current, even after removal from the device they’re powering. Once the battery comes in contact with saliva, an alkalizing reaction can occur and erode through a child’s esophagus — leading to permanent damage and even death.