The Newton, New Hampshire, Fire Department put out a warning about charging iPhones recently, and the message is getting shared all over Facebook.

In a Facebook post, they say that 53 percent of children and teens charge their phone or tablet either on their bed or under their pillow. Bad idea, they say.

The post says that the heat generated can’t dissipate and the charger will continue getting hotter. It could lead to fire.

They want people to check where mobile devices are being charged.

The post went up on June 26, and by Sunday night, it had been shared 31,000 times.