My iPhone XS suddenly overheated and now won't turn on or charge?

Hi everyone!

My trusty iPhone XS suddenly spontanously overheated (while sitting in the cupholder of my car in the shade with nothing plugged into it) and now won't turn on or charge.

I'd really love to fix and keep using this phone, but I also have photos and notes which I haven't backed up recently, so I really want to fix it if possible to at least retrieve my data.

I've heard about problems with the earspeaker flex cable causing boot loops, so I changed that, but it still isn't working.

I then thought I'd replace the battery, and after connecting the battery flex cable and replacing the bracket on top, I could feel the bracket warming up suddenly. So I placed the screen back and attempted to charge and turn on the phone, but still no luck!

Does anyone have any idea what could be wrong and anything else I could try replacing? Could it be the Lightning port or charging flex cable? Or does it sound like my logic board is fried and I have to just retire the phone?

Thanks for any advice or suggestions!

Edit: Does it sound like the charging IC?