John Gage was based on Battalion Chief Jim Page, who helped create the firefighter/paramedic program for LACoFD. Executive Producer Jack Webb wanted to name the character after Page, but he declined. Jim Page died on 4 September 2004 and Randolph Mantooth was one of the speakers at his memorial.
'Emergency!' was truly a family affair because Julie London was at the time married to co-star Bobby Troup and had been hired by her previous husband Jack Webb who was the series' creator and producer.
During the show's run, it was credited with actually saving lives. There were many news reports over the years of children and adults saving people using techniques demonstrated in the series. However in later seasons, the series posted a disclaimer in the credits noting that the medical techniques demonstrated should only be performed by people with proper formal training in them. To further illustrate the need for proper training, one story, "Gifted," had the main characters deal with a patient whose serious medical condition was aggravated by an injury accidentally inflicted by an amateur incorrectly applying a medical technique called a precordial thump and reprimanding him for the error.
The Harbor UCLA Medical Center served as Rampart Emergency Hospital in the series. The hospital is located in Torrance, California. 1000 West Carson Street. This is appropriate, as this hospital (then known as Harbor General) served as the initial training facility for the Los Angeles County Paramedic Training Program.
Paramedics Gage and Desoto sometimes crossed paths with Reed and Malloy from Adam-12 (1968), another Jack Webb show, at Rampart Hospital. In Emergency!: Hang-Up (1972), the firefighters are watching Adam-12: Ambush (1971) when they're dispatched to a call. Throughout the rest of the show, the firemen are on the phone to anyone, trying to find out what they missed.
The series originated when producer Robert A. Cinader was in the Los Angeles area researching for a new medical drama series. There, he learned of the fledgling paramedic program being tested in the Los Angeles County Fire Department. Upon learning the full details of the program and the nature of their dispatches, Cinader immediately concluded the adventures of such a team of special firefighters would be excellent material for a TV series.
Fire Station 51 is in real life Los Angeles County Fire Station 127 located at 2049 E. 223rd Street in Carson. Furthermore, although the actual station crew has never included a paramedic unit, Harbor UCLA Medical Center, the actual hospital that is portrayed as Rampart, is the closest hospital to it so it would be the regular medical facility Station 127 would deal with. The station is still in service with little change. The second Engine 51 used in the show is now retired and on display with the Los Angeles County Fire Museum.
On CHiPs (1977), the fictitious Engine and Squad 51 respond to a motor vehicle accident, in the episode titled "MAIT Game"; moreover, it isn't just two pieces of apparatus with the same number - it is the Ward-LaFrance Engine and Dodge Utility body, even shown pulling out of the 51 Stationhouse. However, the crew is not shown because "Emergency!" had already gone off the air.
During its 8 year run, Julie London was the only hospital cast member to have acted in every episode, while Randolph Mantooth and Kevin Tighe were the only two firefighting cast member to have also acted in every episode.
The radio call sign KMG365, which is said whenever Station 51 is responding to a call, is still a valid FCC call sign licensed to the LACoFD. It appears on the station patches for the crew at Station 127, which was used as the filming location for Station 51.
During his recurring role on Emergency! (1972), the character Officer Vince played by Vince Howard, rotated from being a member of the Los Angeles County Sheriffs Department to a generic police department after Jack Webb had an argument with the LASD.