"Hot as Sun" is an instrumental penned by Paul McCartney and included on his 1970 album McCartney coupled with the non-song "Glasses" (which also contained a snippet of "Suicide", another unreleased Paul McCartney tune). In that album's press release, Paul informs us that it was a "song written in about 1958 or 59 or maybe earlier, when it was one of those songs that you play now and then". The Beatles did so during the Let It Be sessions (included on the bootleg "Wonderful Picture Of You") and Paul also performed the song live with Wings in December 1979.

In 1978, Hot as Sun / Glasses was used as the theme tune to The All-New Popeye Hour. The original track was sped up, played at 45 rpm.