is it possible to create heat distortion in unity?

i was playing a game lately that im pretty sure runs on unity engine, and i noticed some explotions diistorted the image, almost like what happens over a fire that the things behind it seem a bit distorted. if some one knows if this is possible, and maybe has a tutorial or something i would realy like to know how to do it

New one is here with pre-setuped scene:

Like this? http://forum.unity3d.com/threads/50132-Heat-Distortion