'The Kids Aren't Alright' will explore the paramedics' troubled marriage as their ambulance is surrounded by rioters during a public disturbance.
While the ambulance is immobile and the former couple are tending to the injured looters, one rioter - called JJ (Sami Larabi) - escapes from the police and takes refuge in the back of the emergency vehicle.
Jeff (Matt Bardock) is then injured when a fight breaks out between him and JJ.
While tending to her husband's injuries, Dixie is shocked to hear him open up about his estrangement from his children.
Executive producer Johnathan Young confirmed in a statement: "We're always looking for new ways to add value for our loyal fans and this special episode gives us a chance to show a different side to two of our most popular characters.
"Our audience love Jeff and Dixie but we've never had the chance to fully explain the implications surrounding their unusual domestic set-up until now."
'The Kids Aren't Alright' will air on the BBC's red-button service immediately after the medical drama's BBC One instalment on Saturday, July 14.