sudo hddtemp /dev/sd? So I won’t forget (again).
Still don’t know WTF is wrong with the Sensors ACPI temperature display; it’s apparently not using lm-sensors or even sensors, which (AFAIK) is specified by the script, so I have no idea where it’s getting the information, but it doesn’t make any sense for it to show 76C on a cold boot, but if I reboot straight away, 29C. Something’s wrong, but no time to mess with Python I don’t really understand. No time because IT’S A THREE-DAY WEEK, BABY!!