So my G3 started shutting off randomly and the only way to get it to turn back on was by removing the battery and reinserting it. This would only work sometimes. I noticed it heating up very quickly as well.

I called LG even though I knew the phone was out of warranty and they offered to repair it for me for free. I just sent it in. They called it a "courtesy out of warranty repair".

I have a sneaking suspicion that all the techs have been told to accept all repairs for the g3 with this issue because I noticed a large surplus of these issues over the last three weeks. Maybe it's regarding something they did on their end that caused it? I did experience the issue after updating to the latest firmware not a couple days before.

Or maybe they're just being nice?

I'm in Canada if you're wondering. So call up LG if you're experiencing the same issue I was.