Yes, they are saying it was gasper fan. but it was treated as full on Emergency including rapid descent and brace positions. They definitely thought it was something serious.

Only story I have seen is here: Aero-News Network: The Aviation and Aerospace World's Daily/Real-Time News and Information Service

SWA is basically treating it like it was nothing more than a diversion, but all passengers and crew were really quite upset. Flight crew did a great job though.