* CastTheExpert: Most of Squad 3 is actually made up of current and former CFD firefighters who also act as the show's technical consultants.
* TheDanza: Joe Minoso as Joe Cruz, Creator/JeffHephner as Jeff Clarke.
* FakeAmerican: Creator/EamonnWalker (British) as the chief and Creator/JesseSpencer (Australian) as Lt. Casey.
* NoCelebritiesWereHarmed: To the Chicago Fire Department companies housed at the station used for exterior shots, specifically Engine 18 and Truck 15, by reversing the numbers.
* RecycledSet: Season 10's "Count Your Breaths" has flashbacks to the pilot episode and Darden's death. Casey and Griffin (Darden's son) stand outside the same house used in the pilot episode. The show's crew added soot stains and a tarp to the house to make it seem like it had been through a fire.
* YouLookFamiliar: Dora Madison, who plays paramedic Jessica "Chili" Chilton, had previously portrayed informant Alissa Martin on ''Series/ChicagoPD''. [[spoiler: It's later revealed that the two characters are sisters.]]
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