HT-77 Cold Assault Armor was a specialized type of insulated clone trooper armor that was designed for operations in cold environments such as polar regions or planets that were distant from their local sun, such as Orto Plutonia, and although all clone troopers of the Galactic Republic were trained to wear the armor, it was primarily utilized by clone cold assault troopers that were specialized in tactics and operations for such environments during the three-year galactic Clone Wars between the Republic and the Confederacy of Independent Systems.