Each of the four bending disciplines contain a special sub-skill unique only to certain members of each element. Also known as "the cold-blooded fire", certain powerful Firebenders are able to manipulate lightning. Mentally it involves a complete absence of emotion and peace of mind, and physically it requires separating the energies of yin and yang (also an interpretation of positive and negative electric charge). When the forces collide, the bender guides, rather than controls the lightning's direction. Because of this complexity, a lightning attack takes much longer to initiate than standard fire attacks.

Generating lightning involves a circular motion with the arms. Only a select few have this power; so far the only Firebenders in the series who have demonstrated the ability to actively generate lightning are Princess Azula and Iroh. Iroh is also able to combine the waterbending techniques of flowing energy to redirect natural lightning strikes or those that originate from the attacks of other Firebenders by having it travel down one arm, through his stomach, and out his other arm. Zuko seems to have the capacity and desire to learn these abilities, but his emotional turmoil is preventing him from learning.

Re-directing lightning was first demonstrated by Iroh in "The Storm." Creating Lightning was first demonstrated by Azula in "The Avatar State." In "Bitter Work", Iroh teaches Zuko how to redirect lightning, but he refuses to let Zuko practice this technique with real lightining.