As Memorial Day fast approaches, that means everyone’s getting ready for their summer vacations. But if you’re flying with Southwest soon, then you need to be aware of a big policy change on its flights in regards to a daily necessity: portable chargers.

Beginning May 28, Southwest Airlines will require passengers using any kind of portable chargers with batteries in them, including power banks and phone battery cases, to keep them in plain sight while in use. This means that one cannot keep an active portable charger in overhead bins or even bags under the seat — they must be visible at all times during the flight when using them.

Though Southwest is the first US airline to update its rules about portable chargers, it’s possible that other airlines may follow. It’s important to note that this new rule only applies when the battery is connected and actively charging another device. Southwest told Gizmodo that the battery can stay in your carry-on bag if it’s not in use charging another device.

Several Asian airlines already have similar policies in place regarding portable batteries and chargers. The reasoning for the new rules is growing concern over lithium-ion battery fires on planes.

According to the Federal Aviation Administration, there have been 22 verified incidents this year involving a lithium-ion batteries, and 2024 had a record high of 89, with the trend continuing to grow. Since 2006, there have been a total of 620 incidents, and the top culprit involves lithium-ion batteries or battery packs, followed by vaping devices and then cellular phones.

In January, an Air Busan plane had a fire that burned through the roof of the plane as it was preparing to take off, which required all 176 people onboard to be evacuated. Though that particular fire hasn’t had the origin verified, several Asian airlines and Korean regulators updated rules about portable chargers after. Some Asian airlines are much more strict with the rule, like Singapore Airlines and Thai Airways, which have both prohibited using or charging power banks at all while on a flight.

In 2024, smoke from a laptop was seen coming from a passenger’s bag on a flight from San Francisco. Another flight in 2023 from Dallas to Orlando, Florida had to make an emergency stop in Jacksonville due to a battery in an overhead compartment catching fire.

Currently, the TSA bans both rechargeable and non-rechargeable lithium batteries for phones and laptops in checked bags, but have allowed passengers to keep them in their carry-on luggage. But with the new rule from Southwest, those will now need to be out of bags and visible when using them on the flight.

If you’re on a flight and see something on fire, it would be wise to inform the flight crew. They are trained to recognize and respond to lithium battery fires (or other issues) in the cabin, after all.