Matthew Gray Gubler always wears mismatched socks. He believes that it is good luck. This can be seen during the fitness test.
Reid talks about a young girl who survived a rabies infection. He is referencing a 2004 real-world incident of a 15 year old girl, Jeanna Giese, being infected with rabies by a bat and surviving due to what is technically referred to as a fluke of physiology.
A month after being bitten Jeanna began showing symptoms and quickly deteriorated, needing to be put on life support due to paralysis. She was placed in a medically induced coma and given a cocktail of antivirals. She survived the infection and was released 76 days later, unable to walk or speak.
The treatment, which has proven fatal in every use since, is referred to as the Milwaukee Protocol.
The track scenes were filmed at Los Angeles Valley College, at the Monarch Stadium and Track.