A sleeping bag
A sleeping bag was a zipper-closed blanket to sleep in.
In 2151 on the planet Archer IV, a bug found its way inside Commander Trip Tucker's sleeping bag. (ENT: "Strange New World")
In 2152, several crewmembers of Enterprise NX-01 brought their sleeping bags and mats with them to the catwalk when they were forced to stay at the catwalk for several days. (ENT: "The Catwalk")
The term sleeping bag comes from the call sheets of the episode.