The song reached number three on the Billboard Hot 100, becoming Perry's second consecutive top-five single, following "I Kissed a Girl".

It also became Perry's second top-five single in the United Kingdom, Australia, Ireland, and New Zealand, and topped the charts in Finland, Germany, Canada, Norway, and Denmark, among others.

To promote "Hot n Cold", Perry marked the song's live debut with a performance on NBC's Today.

The song's music video, which was directed by Alan Ferguson, was released on October 1, 2008, and features Perry as a bride who is about to marry her fiancé, who experiences a daydream in which she pursues him after he flees from the wedding.

[9] Alex Fletcher of Digital Spy gave the song three out of five stars, saying "this track doesn't live up to the hype surrounding its singer, but the choppy guitars and whooshing synths have a certain charm.

"[10] Jon Caramanica of The New York Times compared the song to "U + Ur Hand" by Pink, which was also produced by Dr. Luke, saying that it does not share the latter's "passion".

[16] As of August 2020, "Hot n Cold" has been certified 8 times platinum by the Recording Industry Association of America (RIAA)[17] and sold 5.8 million copies in the United States, making it Perry's sixth best-selling single in the country.

He manages to escape but walks out to find Perry in her wedding dress surrounded by several other brides carrying baseball bats.

Perry's friends Jadyn Maria and Shannon Woodward appear in the music video as bridesmaids, and her parents Keith and Mary Hudson also make cameos.

Rolling Stone described the music video as "a colorful cat-and-mouse chase that's equal parts goofy and glam.

[32] Perry performed the song live at the 2008 MTV Europe Music Awards in Liverpool, which she also hosted, on November 6 to close the show.

[37] It was also part of the setlist of Perry's Witness: The Tour in a medley with "Last Friday Night (T.G.I.F)", a song from her album Teenage Dream.

[38] The song made its digital debut in the expansion pack of the popular video game, The Sims 2: Apartment Life, released in 2008.

Perry lent her voice to record a special version of the track in "Simlish", the fictional language of The Sims universe.

This unique rendition of the song can be heard on the in-game radio station, adding a touch of mainstream music to the Sims' everyday virtual life.

The clip was originally scheduled to run during the Sesame Street episode "Abby Tries & Tries Again" on December 31, 2010, however, the performance, which was uploaded to YouTube earlier, garnered controversy over the amount of cleavage Perry had on display in the video.

"[41] Perry mocked the controversy shortly afterward in a skit during her appearance on Saturday Night Live as a musical guest, wearing an Elmo-themed shirt which showed large amounts of cleavage.

[43] "Hot n Cold" was used as the Lip Sync for Your Life song on the fifth episode of the third season of RuPaul's Drag Race Down Under in 2023, between contestants Ashley Madison and Bumpa Love.

Atlanta-based metalcore band, Woe, Is Me covered the track for the compilation album Punk Goes Pop Volume 03., which was released on November 2, 2010.