A mirror to keep an eye on a baby in the back seat of a car sounds like a good idea.

But one mother posted a video on Facebook that showed how a car seat can begin smoking if a mirror is trained on it, exposing it to the heat of the sun.

Amanda DeAngelis’ post went viral and has had more than 10 million views.

Police are issuing warnings after seeing the viral video.

Tim Aycock, public information officer for the Matthews, North Carolina police department said the video was disturbing and recommended that parents avoid adding after-market products to a vehicle.

DeAngelis said in an update on Facebook that she contacted Britax, the car seat maker, and they responded immediately to her concern.