Iris' blog post "The Fire within Central City...and Us All" is dated March 13, 2018, the day that this episode aired.
Jaco Birch may be named after J.J. Birch a pseudonym of DC comic book artist Joe Brozowski who worked for a long time on comics about a fire-related character, Firestorm.
Max Adler (Jaco Birch) and Grant Gustin (Barry Allen/The Flash) both previously appeared on the third season of Glee (2009).
When Harry and Cisco were talking about how to defeat DeVoe they said "We alter each bus meta's DNA by performing intercellular surgery.And what? And turn them into chickens?" A similar thing had happened on Red Dwarf, where a old spacecraft had changed Lister into a chicken.
Cisco wears a "TGIF" shirt with a hockey mask logo on it, undoubtedly a reference to Jason Voorhees. Danielle Panabaker (Caitlin) was in the reboot Friday the 13th (2009) as Jenna and Derek Mears played the serial killer was recently on the fourth season of the Flash also as Dwarfstar.