Let me give you guys one better. I fly the mighty CRJ, on which (as on many aircraft) the APU is deferrable. Let's imagine the following scenario: we land with a deferred APU, taxi in, shut down #1, then #2, whose tailpipe promptly catches fire. Now, we have a memory item for this situation and it is this:
AFFECTED ENGINE ---------- Dry motor until ITT < 150C or starter limit
Question: how in blazes am I supposed to dry-motor it, if the APU is deferred?