Question from somebody who hasn't a clue.

Okay so mountaineers are doing their mountaineering thing on, say, Denali. They're up there at a camp, 14,000+ ft. above sea level, for upwards of two weeks. It's sub-zero temperatures. They're building snow shelters to stay warm and have a roof on their heads. All's cool so far. But. How the shitting hell do they wash themselves for two weeks? Lots and lots and lots of wet-naps? What do they do with waste products? For that matter, where do they even go to the bathroom?