Star Wars Holiday Special: 25 WTF Moments
11. Han & Luke Catch The "Sleeping Virus"
The reason for Han Solo being hung upside down is finally given, that in the search for an ancient talisman, he became infected with a so-called "sleeping virus", and the only way to ensure he won't die is to hang him upside down...because reasons.
Luke ends up catching the virus too, so C-3PO gives him the same "treatment", in an incredibly strange subplot that really doesn't seem to make any sense at all. It may be padding, but at least it's better than returning to the Wookie homestead...