As millions prepare to fly for the holidays, the Federal Aviation Administration is warning travelers about a hidden danger in their luggage: lithium-ion batteries. Found in everyday devices like laptops, tablets and even electric toothbrushes, these batteries can catch fire if they overheat or are damaged.

Last July, panic erupted on an American Airlines flight from San Francisco to Miami after a laptop battery in a carry-on bag ignited.

“It was absolute chaos. It truly felt like every man for themselves. And it was terrifying,” said Shilpa Patel, a passenger on the flight. “I don’t know if we’re going to explode. All I know is I need to get out and I need to survive.”

FAA data shows that lithium battery fires on U.S. flights have risen 388% since 2015, now occurring nearly twice a week.

“Any fire at 30,000 feet is unacceptable,” said David Wroth of UL Standards & Engagement, a safety research organization. 

A survey of more than 800 flight attendants conducted by UL found that 87% are concerned about lithium battery risks on airplanes, and more than a third believe airlines should do more to ensure passenger safety. While the FAA requires airlines to include general safety information in preflight announcements, those warnings often don’t address the specific risk of battery fires.

“It’s a balance we probably need to do a better job striking with the airlines,” said Ben Supko, who oversees hazardous materials safety for the FAA. “Passengers don’t fully understand how serious the risk is.”

Supko said passengers need to monitor devices during a flight and immediately notifying the crew if a device becomes warm, discolors, or bulges. Passengers are also warned not to pack lithium batteries in checked luggage, as fires in the cargo hold are harder to extinguish.

“When you don’t know what’s going to happen, you act erratically,” said Patel. “It costs us nothing just to say, ‘Hey, the reason why we’re so serious about this is because it could be really dangerous. It could catch fire.'”

The UL survey also found that one in four passengers admits to packing lithium batteries in their checked bags. It is a dangerous practice for one reason in particular: It would be even harder to put out a fire in the plane’s cargo hold.

CBS News reached out to American Airlines regarding the incident at the San Francisco airport and potential updates to its safety announcements. The airline did not address the question directly but stated that its flight attendants receive thorough and ongoing training to handle emergencies onboard.