"It's basically a micro-sandwich a high-efficiency filter and heat-exchange system. The skin-contact layer's porous. Perspiration passes through it, having cooled the body . . . near-normal evaporation process. The next tuo layers " include heat exchange filaments and salt precipitators. Salt's reclaimed." "Motions of the body, especially breathing," he said "and some osmotic action provide the pumping force. "Reclaimed water circulates to catch pockets from which you draw it through this tube in the clip at your neck
Frank Herbert - Dune