During filming of this episode, series executives and creators had a disagreement over "Scene 49", where Jay emerges from a swimming pool and sees his mom. Some of the executives thought the scene would break the plot tension, and money should not be wasted filming it. Ultimately, the director liked the scene, and filmed it anyway.
This pilot episode was filmed in August 1991, and was produced and finished by autumn 1991. Although the air date was scheduled for June 1992, the series creators pushed for an earlier decision about producing more episodes as the series' stars were 11 years old and growing quickly. By December 1991, the decision was made to go ahead with 12 more episodes, and the rest of Season 1 was filmed in summer 1992.
The primary Downworld scenes were filmed at what is now the revitalized Shipyards District in North Vancouver. The site had been owned by the Burrard Dry Dock Company, and was shut down as an active shipyard in in the early 1990s. In several shots, the skyline of downtown Vancouver can be seen in the distance.
In an effort to make the Upworld script as realistic as possible, the series creators visited a coma treatment facility in Seattle to learn about state-of-the-art therapies.