In a world experiencing increased heat stress, a zero-carbon-emission cooling technology that consumes no electricity, operating instead by shedding heat directly into outer space, would be a groundbreaking advance. However, poor standardization and a lack of transparency is hampering this promising technology, known as radiative cooling. Best practice guidelines, outlined by KAUST leading radiative-cooling researcher Qiaoqiang Gan, could help set the research field back on track.