I have an idea for a vest worn under insulated outer garments that contains tubules that pass air from a compressed air cylinder via an expansion chamber so that the wearer (like a soldier in the desert) is kept cool and dry.
The hot air from the desert is kept out and is thermally insulated from the equitable conditions inside. Any perspiration liquid is taken away by the flow of air.
By using an insulated outer garment the heat load is kept down and so the supply of compressed air lasts longer.
I doubt if this is original but modern materials may make it practical.