A cooler rug is a type of horse clothing designed to help a horse cool down after exercise or sweating. It is made of a lightweight and breathable material that wicks away moisture and allows air to circulate. Cooler rugs are typically used in cooler temperatures, such as during the spring or fall, or in indoor settings. They work by drawing moisture away from the horse's skin and allowing it to evaporate, which helps to lower the horse's body temperature and prevent overheating. Cooler rugs may also feature adjustable straps or fastenings to ensure a secure fit and may come in a variety of sizes and colors to suit individual horses and their owners' preferences.