When Detective West reads out Leonard Snart's name from the mugshot book, Barry says "Leonard? That's almost as bad as Bartholomew." Bartholomew is Barry's full first name.
At one point, Joe mentions that Leonard Snart "showed up every six months." It turns out that Captain Cold appears in every sixth episode in season one (aside from a small cameo in the finale). Also, each time Captain Cold is in a episode in season one, "Rogue" is in the title.
Actors Wentworth Miller and Dominic Purcell who play Captain Cold and Mick (Heat Wave) also starred in Prison Break (2005) as brothers.
Leonard Snart, a.k.a. Captain Cold, is one of Flash's comic book villains. He made his comic debut in May 1957 in Showcase #8. His comic appearance is similar to what is in the subway scene where he is wearing the parka with a fur lining.
Snart mentions a sister. In the comics, Len Snart has a sister, Lisa, also known as the Flash rogue Golden Glider.