I once had a peculiar issue whereby render jobs would complete fine when I was sitting at my desk, but every time I tried to do an overnight run I'd come in in

I once had a peculiar issue whereby render jobs would complete fine when I was sitting at my desk, but every time I tried to do an overnight run I'd come in in the morning and find the machines had rebooted a mere hour after I left. Of course it turned out they were overheating as soon as the HVAC was turned off after office hours.