There are two types of natural hat tricks. The first definition is a player scoring three goals in the course of a single period. The second definition (and more common) states that a player scores his three goals all in a row, with no other player scoring a goal in between his goals.
The record in the NHL for the fastest natural hat trick occurred in 1952 by Chicago Blackhawks Bill Mosienko. He scored a natural hat trick in 21 seconds of the game. In 2010, Mark Del Ville of the AIHAL's Mid Ice Crisis scored the fasted recorded natural hat trick in 17 seconds. A regular hat trick in hockey occurs when a single player scores three goals in the course of an entire game, but other players may score goals in between that player's goals. In the NHL, a hat trick is usually rewarded with fans tossing their hats down onto the ice. It is said this tradition started in the 1950s.