The Blaklader Slim warming bodywamer women 3881-2032 uses smart thermal technology from Clim8� that can detect when your body temperature drops and then warms you up. The padded vest has a two-way zipper and knitted polyester on the sides to further increase comfort and freedom of movement. The customizable built-in technology uses a thermostat and computer to monitor your body temperature and uses battery-powered elements to regulate the heat within the vest.