This effect was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
Based off the filter Burninator by Richard Bartlett, this filter allows for a great deal of flexibility for the user because of its being able to generate the flames on a transparent background.
This is especially useful on a Layer in Photoshop since you can draw something that matches the image underneath and then set it on fire.
From Richard Bartlett's filter description:
Flame generator with optional time slider for seamless animated sequences.
fire flame burn hot animation transparent