Holly Aird (Dr. Wharton) was expecting her second child during season four which is why in season four her character is nearly always seen standing behind something (or someone in walking shots) or wearing large coats and lab coats.
The first season secured strong ratings, with episodes Burn Out: Part 1 (2001) and Burn Out: Part 2 (2001), receiving 8.4 million viewers and a thirty-eight percent audience share. Persistently high ratings meant this show was renewed each year for either the summer or winter schedule.
All the episodes were two hours long, shown as two one-hour parts on consecutive days of each week.
A spin-off from the series, titled The Body Farm (2011), revolving around forensic scientist Eve Lockhart (Tara Fitzgerald), was announced by the BBC in January 2011 and ran for just one season.
Episodes Special Relationship: Part 1 (2002) and Special Relationship: Part 2 (2002), written by Stephen Davis and directed by David Thacker, received an International Emmy Award.