Portable chargers and power banks might be useful additions to your carry-on luggage, but they’re also a potential fire risk. Now Southwest Airlines is tightening rules around their use on board aircraft.

Southwest Airlines will introduce a new policy requiring portable chargers to be visible when they're in use onboard.

Passengers on Southwest Airlines flights will soon be required to keep their portable chargers in plain sight while using them because of concerns about the growing number of lithium battery fires.