I've always seen these warnings on any can of aerosol hair spray, bug spray, or anything else that comes in an aerosol can.  Always says not to leave in extreme temperatures.  I've never heard of anything happening.. .but guess what... it did.

Check out the video from the destruction from a can of dry shampoo that exploded while in a console of a hot car.

My first thought was.. .wow!  That can actually happen!  No one was in the car at the time of the explosion.  And quite honestly, if there had been, it probably wouldn't have happened.  The car would have been cooler had someone been in the car.  But what if the owner had just returned to the car just before the can blew.. that could have been disastrous.

Via Youtube.com

Luckily, that was not the case, but the mother of the girl who owned the dry shampoo is urging anyone to heed the warning. Like- don't let this happen to you sort of thing.