Overheating issues topic

my Samsung S3 gets over 100 degrees when data is on and the battery starts to drain really fast and will drain even if it's plugged in. What do you think is wrong and how can I fix it? Thanks to all who answer.

I have already done everything from power saving to lowering screen brightness etc. Even when the screen is off, the same thing happens as long as data is on! Data is off and the phone cools down and everything is fine. This happens all the time.