Left PC on to upload large video, black screen and unresponsive when I came back the next morning. Very hot

MSI Prestige Laptop. AMD Ryzen AI 9 365 Radeon 880m Windows 11 pro.

I left a large video uploading to YouTube overnight. The laptop was plugged in to wall power.

I've done this before with other PCs with no problem and I feel like leaving large files to upload is a relatively normal thing to do.

I had no programs open other than the browser to upload.

The upload did finish without a problem in that regard.

When I came back in the morning the screen was black and all keys and mouse were unresponsive. Holding down the power button for 30 seconds+ did nothing.

The vent area was very hot.

After holding down the power button did nothing I unplugged it and left it for a few hours. It booted up like normal later on and seems to be fine.

It appears to have just overheated, but why? I leave my work computer on all the time, sometimes for days, sometimes with apps running and nothing has ever been a problem.

What about leaving it to upload would cause it to overheat like that? Uploading shouldn't be a CPU or GPU intensive process, what would make it hot at all?

It is a two week old PC, the vent holes are not clogged, it isn't full of dust or dirt.

It was sitting on a glass coffee table with the back edge propped up a little so there was plenty of airflow under the intake vents and nothing blocking the outflow vents.

Thank you.