First introduced in 2014, super cool materials reflect a broad spectrum of light, in much the same way as mirrors or white paint do. In the crucial 8–13-µm part of the infrared spectrum, however, they strongly absorb and then emit radiation. When the materials point at the sky, the infrared rays can pass straight through the atmosphere and into space. That effectively links the materials to an inexhaustible heat sink, into which they can keep dumping heat without it coming back. As a result, they can radiate away enough heat to consistently stay a few degrees cooler than surrounding air; research suggests that temperature differences could exceed 10 °C in hot, dry places. Paints, plastics and even wood can be engineered to stay cool in direct sunlight.
The future for use of super cool materials looks promising with several researchers and companies (SkyCool Systems, MetaRE, InventWood, etc) working on finding and improving upon them.