This exact thing has happened to me multiple times and I've researched it a tremendous amount... My phone isn't rooted, and I've noticed that it seems to happen only in certain places, and gets worse if I am actually using the phone but it doesn't need to be 'used' for the hot drain to occur. I think it only happens when your in a low-reception area, it seems to happen only in a few select locations for me.... And thankfully it doesn't happen at all at my home. It gets burning hot, doesn't stop.. and gets worse and worse unless I remove the battery and turn the phone off. If I'm using data in a low reception area it's like a runaway train... Starts to drain, gets tremendously hot and doesn't stop unless I take some kind of action to stop it. Also, I believe it contributes to a massive data drain for me. I have unlimited data but have been throttled because of massive amounts of data consumption due to this problem. It's driving me insane, I don't know what to do about it... I love this phone so much but this is a glaring problem. 11GB of data last month and already started being throttled this month, and I BARELY use the data on this phone!!