Desert-dwellers use all kinds of tricks to keep cool, from burrowing during the day to using reflective hairs to beat back the sun’s rays. Some birds have a different strategy, Science News reports: They use their big, veiny beaks to offload extra heat. Researchers in South Africa took thermal images of southern yellow-billed hornbills at different temperatures—and above 30.7°C, their beaks lit up like a lightbulb. Once it reaches this temperature, the veins in their beak (above) dilate, allowing more blood in and more heat to flow out, they reported this week in PLOS ONE. Toucans, with their bigger beaks, can do the same thing even more efficiently. So why don’t hornbills have a bigger air conditioner? Diet may be the key, researchers say: Hornbills need a sturdier beak to rip off tree bark in their search for insects.