Travelers will need to follow a new rule regarding juicing up their devices while flying on Southwest Airlines.

The Texas-based airline will be "requiring customers to keep portable charging devices visible while in use during flight," a Southwest spokesperson said in a statement to Fox News Digital.

"Using portable charging devices while stored in a bag or overhead bin will no longer be permitted," the spokesperson added.

"Nothing is more important to Southwest than the safety of its customers and employees."

A passenger's battery charger recently caught fire on a JetBlue flight from Florida to the Bahamas, Business Insider reported.

Starting May 28, Southwest Airlines is mandating that customers' portable chargers remain visible during flights to enhance safety. (Kevin Carter/Getty Images)

Smoke and flames erupted in the cabin of the flight due to the portable charger overheating in the passenger’s carry-on luggage.

Portable chargers, or power banks, are not allowed in checked bags but can be packed in carry-on bags as they have lithium-ion batteries, according to TSA.

The FAA website notes that "all lithium-ion batteries are capable of overheating and experiencing a process called thermal runaway."

Southwest Airlines has introduced a new rule requiring portable chargers to be visible during flights. (iStock)

"Thermal runaway can occur without warning as a result of various factors, including if the battery is damaged, overheated, exposed to water, overcharged, or improperly protected."

The policy will begin on May 28. Customers with the Southwest app have shared that they are receiving notifications about the policy already. 

Portable chargers or power banks are not allowed in checked bags but can be packed in carry-on bags as they have lithium-ion batteries, according to TSA. (AP Photo/David Zalubowski)

In the "r/SouthwestAirlines" forum on Reddit, a user shared a screenshot of the notification, titling the post, "I had no idea this was an issue."

The post said, "Got this pop-up for the first time, and I'm baffled."

The notification showed a battery graphic saying, "If you use a power bank during your flight, keep it out of your bag and in plain sight. Do not charge [the] device in the overhead bin."