Honestly, who needs a heat haze 'in the sky'! ;\)
Actually, a heat haze is above a flame of a fire place or a torch,
or on day times, close above the street.
The heat in a desert has to be achieved by a different trick then!

The picture looks nice and atmospheric! \:\)

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt