Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
The best way to determine whether it is a battery issue, is to swap out the battery, and see if the problem ceases that way. Batteries do sometimes short-circuit internally... they can overheat, or even sometimes, explode or burst into fire and flames.
So that might be both the best, ***** ***** safest, way to determine where the fault is... and if the new battery also produces a heated camera or heats up itself, pull it out at once, for safety.
Let me know how it goes, please. Thanks.