A cool roof is designed to reflect more sunlight than a conventional roof, absorbing less solar energy. This lowers the temperature of the building just as wearing light-colored clothing keeps you cool on a sunny day. Conventional roofs can reach temperatures of 150°F or more on a sunny summer afternoon, Sun. Under the same conditions, a reflective roof could stay more than 50°F (28 °C) cooler. This can save energy and money in buildings with air conditioning, or improve comfort and safety in buildings without air conditioning, by reducing heat flow from the roof into the occupied space. Most cool roofs have high “thermal emittance”—the ability to shed heat by giving off “thermal infrared” radiation. Nearly any type of building can benefit from a cool roof, but consider the climate and other factors before deciding to install one.