Testing or servicing? think

1) Thermometer for checking the temperature
2) Blower for blasting the tumbleweed out from the back
3) (if moveable) Dustpan and brush for cleaning up the mess underneath and behind
4) Suitable cleaning materials (if you're so inclined)
5) Check mains cable and plug (and fuse)
6) Carry out electrical safety test (of course)

If you don't inspect ... don't expect.