"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 Dr. Luke and Benny Blanco for her second studio album, One of the Boys (2008). The track 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.The song received mixed to positive reviews from music critics.