When Crystal Frost was a student at Hudson University, she fell in love with one of her professors, Martin Stein. Stein however, rejected Frost's affections. Crystal was devastated and her low self-esteem eventually developed into a hatred of all men.
After college, Frost became a scientist working on the Mohole scientific project in the Arctic. At this time, she was reunited with Stein. During their research, Crystal was accidentally locked inside a thermo frost chamber, and as a result was transformed into a psychotic killer with the ability to project waves of freezing cold. From this point forward, she began calling herself Killer Frost.