The stillsuit is a special suit that first appeared in the science fiction novel Dune from 1965. It was created and is used by the Fremen who live in the desert planet Arrakis.
It is a special body-enclosing suit designed to collect and recycle all the moisture the body releases, from urine, feces and sweat, to the exhalation of water vapor in the breath.
The special fabric of the suit is a micro-sandwich designed to dissipate heat and filter wastes while reclaiming moisture. The water is then held in catchpockets and made available to drink through a tube.
A Fremen in a well-kept suit can survive weeks in the desert without any other source of water.