Despite its come-on title, The Day the Earth Caught Fire is an intelligent, disturbing piece of speculative fiction. Through the eyes of British reporter Peter Stenning (Edward Judd), we learn that both the U.S. and the U.S.S.R. have simultaneously set off nuclear explosions to test their efficiency. The twin blasts have caused the Earth to go off its axis. The result is a disastrous upheaval in the balance of nature; floods and fires being the principal plagues. With the end of the world staring everyone in the face, chaos reigns. The only hope lies in another massive nuclear explosion, which will hopefully rebalance the Earth. The film ends ambiguously, with viewers allowed to decide for themselves whether or not the world has been saved. In the original prints of The Day the Earth Caught Fire, the opening and closing reels were tinted yellow, representing the scorching heat beating down on the frightened populace.
~ Hal Erickson, All Movie Guide