Producer Robert A. Cinader saw Randolph Mantooth in a small role on "The Bold Ones" opposite Hal Holbrook that led to his decision to cast him as paramedic John Gage on "Emergency!" Randolph Mantooth and Kevin Tighe were part of a paramedic team assigned to Squad 51 of the Los Angeles County Fire Department. Responding to accidents or dangerous rescues in an "emergency room on wheels" with directions via biophone from medical personnel back at the hospital, the paramedics performed Advanced Life Support (ALS) techniques to stabilize injured, ill, and dying patients before transporting them to a medical facility.