"Hot n Cold" is a song by American singer Katy Perry from her second studio album, One of the Boys (2008). She and Max Martin co-wrote the song with its producer Dr. Luke, with additional production from Benny Blanco. The track was recorded in December 2007 at Dr. Luke's Studios and Legacy Recordings, both based in New York City, New York, and Conway Recording Studios, based in Hollywood, Los Angeles. "Hot n Cold" was released as the album's second single on September 9, 2008, and was the first single to be released after the album. "Hot n Cold" is primarily a pop record in the styles of dance-pop, disco, and pop rock, and its lyrics address an unstable romantic relationship caused by a partner's mood swings.
"Hot n Cold" charted at number one in Austria, Belgium, Canada, Chile, the Czech Republic, Denmark, Finland, Germany, Hungary, the Netherlands, Norway, Poland, Romania, Slovakia, and Switzerland as well as the top five in Australia, Bulgaria, Iceland, Ireland, Israel, New Zealand, Sweden, the United Kingdom, and the United States. It additionally was certified diamond in Brazil, Australia, and Canada, and multi-platinum in Denmark, New Zealand, Norway, the United Kingdom, and the United States. "Hot n Cold" is one of eight songs by Perry to sell over 4 million digital copies in the US, the others being "I Kissed a Girl", "California Gurls", "Teenage Dream", "Firework", "E.T.", "Dark Horse" and "Roar".
