iPhone 12 constantly overheats and shuts down when idle

I recently purchased an iphone 12 because i didn’t really want to waste money on newer ones knowing i might break it, and when i say recently i mean 2 months ago i got this phone.

Anyways my problem is how it constantly overheats even when I’m not using it, and it turns off saying i need to wait for it to cool down. Now i understand apple has that built in to stop your phone from overheating but I don’t understand WHY my phone is overheating when its just sitting on my bed in front of a fan just charging.

it gets ridiculous i cannot even take a 10 minute phonecall with my own mother because it overheats and turns off, once it didnt cool down and turn back on for a whole 20 minutes and sometimes when it does this its not even hot its like warm, and other times it does this my phone will actually be hot and lagging.

I’m wondering any iphone 13 or up users recommend getting the newer models or do all of them do this?