Several snake species sport horn-like appendages over their snouts and/or eyes. Although these structures have recently attracted scientific attention, their functional significance remains unknown. One hypothesis holds that the cephalic appendages may work as heat radiators/dissipators, keeping temperature stable during sudden changes in heat load. Following this hypothesis, we expect that horns heat and cool at different rates than the rest of the head and have a stabilizing influence on brain temperature. To test this idea, we used water-filled 3D-printed head models of vipers, the snake family with the highest number and diversity in horned species. After validating our method, we compared the heating and cooling of an array of hornless and horned models in a temperature-controlled environment and monitored horn and head temperatures. Our preliminary results show that horns indeed heat and cool at different rates than the rest of the head. However, the brain region of models with and without horns heated and cooled at similar rates. Therefore, unless they are accompanied by a special blood vessel cooling and countercurrent exchange system, the horn-like structures of snakes probably cannot function to regulate head/brain temperature. We are currently investigating the possibility of such rete mirabile in snakes, using micro-CT scanning and by monitoring heating and cooling behaviour of snakes in-vivo.