In the interview "Seeing the Blossom", Dennis Potter comments that he wrote "Cold Lazarus" and its prequel "Karaoke" based on the simple writer's premise: "If you wanted to make the world a better place, who would you kill?"
When Dr. Glazunov destroys Daniel Feeld's frozen head at the end, the wall screen still displays his voyage through the tunnel of light to heaven, despite not being plugged into anything any more.