Dirk Morgna's father owns a nuclear power plant, where Dirk works as a helper, when he was delivering supplies to one of the plant's scientists, Dr. Zaxton Regulus, the machine the scientist is working on explodes, killing one of the workers. Dr. Regulus blames the accident , his sudden subsequent dismissal by Dirk creating an interruption that is what the scientist believes.

the scientist tries to get revenge as he tries to teach a lesson on Dirk by throwing him in an atomic reactor for the accident he caused; however, due to Dirk's unique "one-in-a-million genetic structure" instead of killing him allowed him to survive the radiation instead this inccident gave him the power to generate heat and light.

When Dirk tried to apply for the Legion, as Sun Boy, but is quickly rejected as he has only demonstrated his ability to generate light. He is later accepted when he shows he has developed a heat-generation ability.