bivouac

bivouac \BIV-wak, BIV-uh-wak\, noun:

1. An encampment for the night, usually under little or no shelter.
2. To encamp for the night, usually under little or no shelter.

Rob had made his emergency bivouac just below the South Summit.
-- David Breashears, "Death on the mountain", The Observer, March 30, 2003

They were stopped by savage winds and forced to bivouac 153 m below the day's goal.
-- Erik Weihenmayer, "Men of the Mountain", Time Pacific, February 4, 2002

Bivouac comes from French bivouac, from German Beiwache, "a watching or guarding," from bei, "by, near" + wachen, "to watch."