Pretty clever idea, eh? (And warm during those cool April games!)
Well, it seems the inventor of Fan Hands, Marc Jones, is a native Central New Yorker, and charities are now jumping on board selling these. The Carol M. Baldwin Breast Cancer Research Fund had pink ones made. The Chiefs were among the first organizations to sell these novelties.
You can learn more about it here (Reith/Marc Jones and Mark Soderstrom).