"Hottest Sun in the Universe", Flammbron acts as a home planet for a species of beings that resides on its incandescent surface and survives on the respiration of atomic flame. Relatives of the Flammbronians of Flammbron observe Superboy gaining a similar power of atomic breath (SB No. 115/1, Sep 1964: "The Atomic Superboy!") and Superboy saves one of their lives.
When Superman is infected by Virus X by Lex Luthor, he is taken by coffin to Flammbron for cremation (Act No. 365/1, Jul 1968: "Superman's Funeral!"), but remembering Superboy's sacrifice for their relatives, the Flammbronians save him from the fiery fate and he recovers from the virus because of White Kryptonite exposure due to the actions of Bizarro (Act No. 366/1, Aug 1968: "Substitute Superman!").