"Hot n Cold" is a song by American singer Katy Perry. The song was written by Perry, Dr. Luke, and Max Martin and produced by Luke and Benny Blanco for her second studio album, One of the Boys (2008). It was released as the album's second single on September 9, 2008. The lyrics address an unstable romantic relationship caused by a partner's mood swings.

Katheryn Elizabeth Hudson, known professionally as Katy Perry, is an American singer, songwriter, and television personality. She is known for her influence on modern pop music and her camp style, being dubbed the "Queen of Camp" by Vogue and Rolling Stone. At 16, Perry released a gospel record titled Katy Hudson (2001) under Red Hill Records, which was commercially unsuccessful. She moved to Los Angeles at 17 to venture into secular music, and later adopted the stage name "Katy Perry" from her mother's maiden name. She recorded an album while signed to Columbia Records, but was dropped before signing to Capitol Records.