Lieutenant Carl Jaeger was a male Human Starfleet officer who lived during the mid-23rd century. He served in the sciences division aboard the USS Enterprise under Captain James T. Kirk, during a historic five-year mission that starship undertook. He was one of the ship's meteorologists, and was fluent in the German language. Later, he called Kirk's attention to Trelane's wood fire, which gave off no heat despite its steady burn. (TOS: "The Squire of Gothos" )