After you've rotated your text, flatten all the layers:
Layer -> Flaten Image
Now it is time to start adding the effects.
Filter -> Stylize -> Wind; (From the right)
Rotate the canvas back to the original way you had it.
Image -> Rotate and choose 90 degrees CW.
Again add the Wind filter, but this time from the left.
Filter -> Stylize -> Wind; (From the left)
Next we will add some ashes to fly around your fire
Filter -> Noise (Add Noise...), I used about 15% with Gaussian Distribution.
And finally add a ripple effect to add some heat to the fire
Filter -> Distort -> Ripple, (30% medium)