Arabian oryx

In extreme heat, an oryx's body temperature can reach 46.5 °C (115.7 °F) and drop to 36 °C (96.8 °F) on cold nights.

An excerpt from the article 22 facts about Arabian oryx

When the temperature rises above 40 °C (104 °F), the oryx does not sweat or lose moisture to cool itself. Its body temperature rises above 45 °C (113 °F), and its brain is cooled by blood flowing through a network of blood vessels (rete mirabile), forming a kind of autocooler. In addition, the oryx can control the function of the kidneys.