The episode takes place in September, 2020, when it was originally intended to air. Because of the pandemic, it was delayed until the following January.
Jennifer Love Hewitt was pregnant in real life during season 4.
At the conclusion of this episode, this message appears with a photo. "In Loving Memory of John Kemmler 1958 - 2020"
Hen states "Welcome to triage" to her crew when entering the bus full of injured people. Triage is a method that EMS providers and Emergency Department staff use to categorize the level of illness or severity of wounds that patients suffer during a mass casualty event. This allows providers to separate the severely injured/ill from those that have minor injuries.