What Happens to The Hats after a Hat Trick

One of hockey’s greatest traditions, the tossing of hats on the ice when a player scores thrice evolved from local businessmen handing out fedoras to players about 90 years ago.

During the 1970s, fans built on that tradition by tossing hats on the ice, and the NHL eventually amended its rule book to say that “articles thrown onto the ice following

Source:
http://sports.yahoo.com/nhl/blog/puck_daddy/post/Hockey-mystery-What-happens-to-hats-thrown-for-?urn=nhl,167824