The song meaning has been a topic much debated amongst fans. There are various suggestions, such as it relates to sexual preferences or it is to do with dying. Some state 36 Degrees refers to the average human body temperature being generally accepted as 37 °C (99 °F), and that the narrator is dying, or losing the will to live after being dumped by a partner. Singer Brian Molko is stated to have said before a performance "The average body temperature is 37 degrees. This is a song called 36 Degrees", further adding to the speculations. However, the term 36 Degrees also means two people who are not getting on in urban slang; therefore the idea of the song being written for a break-up could well be true. The other numbers mentioned have been said to just be random, "they just seemed to fit" according to the band.
The music video, directed by Chris Cunningham, was shot primarily in a scuba diving pool and shows band members performing the song underwater. Some scenes were shot in a swamp-like area and show Brian Molko singing the lyrics with just his head above the surface of the water. Later band members revealed that this video was extremely hard to shoot and they would never make one underwater again. Chris Cunningham also claimed in an interview that he made Molko cry, having him in the frigid water for hours.
The song was part of the band's repertoire prior to the release of their album and it was a regular until the Sleeping with Ghosts tour. A reworked version, performed at a much slower tempo, was debuted at the band's 10th anniversary show at Wembley Arena in 2004. This version was played during the band's 2005 South American tour and the early legs of the Meds tour. It was also released as a B-side to the "Because I Want You" and "Song to Say Goodbye" singles under the title "36 Degrees 2005".