Innerpartysystem is an American electronic rock band. The group consists of Patrick Nissley, Jared Piccone and Kris Barman. The band is well known for their live performance lighting largely by Andrew Nissley and videos directed by Stephen Penta.

"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.