Freeze Lightning was first introduced when a man was hit by it during the convention held at Kramer Innovations' facility by Dr. Malcolm Tunney. Rodney McKay named it such when talking privately with Tunney. Later, Tunney took credit for naming it, despite Rodney's protests that the name was his. Ironically, Bill Nye later said that the name was stupid and Rodney passed the blame onto Tunney.
Freeze lightning is caused by the matter bridge created by Malcolm Tunney to combat global warming. It occurs because the machine's massive heatsink fails to draw warmth from the surrounding area in a uniform fashion. Instead, it would sporadically draw massive amounts of heat from one direction, creating the freeze lightning effect. Freeze lightning has the ability to instantly freeze everything in its path. The first time it hit someone, it froze their entire left side. A bolt also damaged the communication systems in the facility, and later, froze the doors to the hallway in which Dr. Jennifer Keller was trying to contact Stargate Command with a cellphone. The same bolt also struck a water pipe. Cold and wet, Jennifer began going into hypothermic shock, but was luckily saved by Rodney McKay. (SGA: "Brain Storm")