Portable air conditioners have wheels for positioning the units within a space or rolling them between locations as cooling needs change. They supply cool, dehumidified air for spot cooling, supplementing central AC, and providing room-specific cooling in commercial and industrial applications. Units with a heat pump or electric heat also produce heat for all-season climate control in moderate climates. When used for cooling, these portable air conditioners are typically ducted to discharge hot exhaust air to the outdoors. Heavy-duty units are sometimes used without ducting for spot cooling people at factories, warehouses, and outdoor events.