WATCH YOUR RED BULL

More than 20,000 people went to the ER in 2011 with anxiety, rapid heartbeat, seizures, or heart attacks after downing the highly caffeinated beverages—more than twice the number from four years earlier. More than half the patients had negative reactions to the drinks alone, which include Monster, Red Bull, and Rockstar, while others experienced trouble after combining them with alcohol or prescription drugs, such as the stimulants Adderall and Ritalin. People “don’t realize the strength of these things,” says a spokesman for the American College of Emergency Physicians.