I used to put my Windows 10 laptop in my bag at night, but every now and then I'd realise later that it had powered itself on, the fans were going nuts, and it was obvious really, really hot!

I don't think it was actually installing updates (I use Enterprise eds), though I've no idea what it was doing. I've since started leaving it plugged in on my desk, and haven't noticed it turning itself on at all since then. Weird.

Seems mad they'd try to install updates while not on AC power, and I'd think it's fairly common for sleeping laptops to be placed in a bag overnight.