That heat is quite a simple thing to recreate actually
(i'll assume your using Paintshop 6/7/8 but i'm sure you can figure a way to do this in other programs too)
firstly take a raster greyscale (black->white)
then using something likst AnimatorShop 3 make a wave animation with it, not too complex that spans over say 8-15 frames (not point in making it hyper complex. And export them as individual jpg or bitmaps.
After this create a grey map (rgb(128,128,128) for best results) and then do a non-uniform noise of around 15% on it...
no import each of the Wave animated frames you create, and now combine them as the Alpha Mask for the image and save the alpha channel to disk.
finally export each frame as TGA 32bit, now load each as an image/texture in a loop like you would for sprite animation within DB Standard
a nice cheap heatwave look
Perhaps its not the same as a shader but it certianly as hell is alot cheaper processor wise ... and you can also apply it like a particle effect far easier
Within the Epic battle of the fates the Shadow and the Angel will meet. With it will harbinger the very fight of good vs evil!
