An iPhone 4 supposedly blew up because it was too hot and burned a man's hand, and his table. This is according to Omar Huartas who made the video you see above. Omar says the phone became very hot while his wife was holding it. Eventually, the battery swelled so much that it popped the rear cover off the phone. They put the phone on a table and it left visible marks, and somewhere in there it supposedly burned his hand. He also says enough smoke came out of the phone to set off the fire alarm.
This seems very odd and we'll need more evidence before we can say if it's true or not. Huartas apparently went to the Apple store to get a replacement phone so it's unclear where the original phone is. We've seen a lot of people claim to be injured by their smartphones before, only to find out later it was a fake. The video is simply a compilation of photos, decorated with animation of smoke and fire. So...what really happened?