In ice hockey a hat-trick is when a player scores three goals in a game. Although people may consider a hat trick as three goals scored in a row, this is commonly confused with a natural hat trick (see below).
If a member of the home team in ice hockey scores a hat-trick, fans acknowledge it by throwing their own hats from the stands onto the ice, often causing a delay in play. This custom was started in Guelph, Ontario with the Guelph Biltmore Mad Hatters, sponsored by Biltmore Hats. Biltmore Hats would award any player scoring 3 goals in one game a new hat to award this accomplishment.
In 1996, the Florida Panthers fans celebrated goals (not just hat-tricks) by throwing plastic rats onto the ice, which were then cleaned up by men dressed in Orkin (a pest control company) exterminator outfits. The history of this goes back to an incident in December 1995, when Scott Mellanby scored what teammate John Vanbiesbrouck dubbed a "rat trick" after ridding the Panthers' locker room at Miami Arena of an unwanted rat with his stick on the same night he scored a pair of goals. When Mellanby scored a hat trick in a later game some fans threw plastic rats on the ice, mimicking the octopus thrown by Detroit Red Wings fans, and the practice soon became universal for Panthers home goals. The NHL later responded by banning the throwing of objects onto the ice by fans at the cost of a penalty for the home team, but specifically allowed the traditional throwing of hats to continue. There appears to be some leeway with regards to what can be thrown onto the ice following a hat trick, as witnessed after the Nashville Predators' Paul Kariya scored a hat trick on April 18, 2006 when two catfish were thrown on the ice and no penalty was given.
Former Blackhawk Bill Mosienko holds the NHL record for scoring the quickest hat trick. He scored 3 goals in 21 seconds against the New York Rangers on March 23, 1952. Wayne Gretzky holds the NHL record for most hat tricks (all of them natural) in a career by 50. Because of this, it is sometimes unofficially known as a Wayne Gretzky hat trick.
A natural hat trick is when a player scores three consecutive goals in the same game. A player accomplishes a Gordie Howe hat trick by scoring a goal, getting an assist, and getting in a fight, all in the same game though Howe only recorded two in his career. While this description has remained popular, it doesn't satisfy the conditions of a hat trick.
Mario Lemieux once accomplished what was unofficially referred to as a "Mario Lemieux hat trick" in 1993, by receiving radiation treatment for Hodgkin's lymphoma the day of the game, and then scoring a goal and an assist that night against the Philadelphia Flyers. He has also recorded a "5-goal hat trick" (or the "ultimate hat trick", or a "quintella", or "Lemieux Cycle") in which he scored in five possible game situations in one game, on 31 December 1988 against the New Jersey Devils. He scored on a powerplay, shorthanded, even strength, penalty shot and an empty net goal. Calgary Flames star Jarome Iginla came close on February 23, 2003 against the Phoenix Coyotes: he scored on a powerplay, shorthanded, even strength and an empty net goal, but Mario Lemieux is the only player to score the "Quintella" in NHL history.