Surveillance footage obtained from a Las Vegas phone store shows video shows an iPhone exploding on a desk while an employee sat just a couple feet away.
The employee quickly jumped up to get help as the phone burned itself out on the desk in less than 20 seconds.
The phone screen was being replaced after it cracked due to heat damage as the battery expanded.
The store is not being identified.
Paul Tartaglio owns Gadget Repair. While it wasn't his shop, he says he has seen badly damaged batteries due to heat in the Las Vegas desert.
He has seen a phone explode before but "It takes a lot for it to explode."
The biggest issue he sees the temperatures rise into the triple digits in Las Vegas are the cracked screens from warped batteries.
"Over time, the batteries heat up and bloat," Tartaglio said. "The problem is when it bloats up just a little bit, it can cause your screen to crack a lot easier."
While he says it's extremely difficult to predict when a battery could explode, Tartaglio said the key is to keep phones out of direct sunlight during the summer.
Not only can it lead to explosions in extreme cases, but it can also shorten the life of the battery —especially after the phone issues a temperature warning a few times.
Smart phone users should also avoid overcharging devices, which can generate extra heat in the battery.
Tartaglio also recommends people use replacement batteries directly from the phone's manufacturer, saying they are often more reliable than aftermarket batteries and typically aren't any more expensive.