User blog comment:Poisonshark/Custom Champion: Connolly, the Wurm/@comment-7709681-20140812202702/@comment-25235491-20140813193000

The total is multiplied by the Heat percentage. Meaning that you can cast it while venting out and not at full heat, for reduced damage. It is badly formulated though, when I think about it. But the Heat is a multiplier to all the damage.