A Fleece is a type of jacket made of soft material. It's a type of apparel worn by the Tau'ri when they're in cold environments.
History
The North Face and Arc'teryx are two of Earth's apparel companies that produce fleeces. Personnel of the Stargate Program have worn their brand fleeces in Antarctica. (SGA: "Rising")
Before they left Earth in 2004, Atlantis expedition members wore fleeces while they were stationed at the Antarctic outpost. (SGA: "Rising")