The painting featured in the movie at the beginning is titled "The Triumph of Death".
When shooting the scene where Paul interrogates Will, the boom operator had to sit in a tree for half the day to record the audio correctly.
Shults' simplest explanation of the films title, which he spoke of at a screening in Chicago, is that the title came to him early on in the writing process, before characters and plot were fully developed, and it stuck with him. He has also said it can represent the need to rest but at night, fear and anxiety can take over.
There is a picture hanging in the hallway that is a tribute to Lil Wayne's Carter IV.
One of the pictures in the hallway is of Bill Withers, the singer famous for the hit song, "Lean on Me."
Both Carmen Ejogo and Riley Keough also play in the anthology series The Girlfriend Experience, though their characters appear in separate seasons of the show.
Joel Edgerton's character states that he was a teacher before the world started falling apart. Joel Edgerton's character was a teacher in the movie Warrior (2011).