Hot n Cold was released in 2008 as a single from Katy Perry's album One of the Boys and became one of her early worldwide hits. Written about a partner whose mood and commitment keep reversing, its list of opposites made the chorus highly quotable. The hook later spread online as shorthand for indecision and mood swings, with creators cutting the short chorus over before and after clips, contradictory texts and sudden personality changes. Its recognisable melody and clear lyric keep it useful long after its chart run.