In deserts, you can find a multitude of animals that have adapted to the extreme heat and lack of water.
Lizards in deserts have thin legs that take very little of the heat from the ground on which they tread. They also are the color of the surrounding rocks, making them very hard to spot, and when they are spotted you can barely see them and will lose sight of them in a few seconds.
Black Vultures urinate on their feet to keep cool. They also fly up on cold thermals above the dizzying desert heat below. Birds have a hard time hunting for lizards because they are so high up and the lizards are small and sand colored. They have adapted to this by gaining superb eyesight.
Frogs and toads live in deserts. They only come out of their burrows when it rains, When it does not rain, they are dormant.
A few other adaptations are, migration, estivation (sleeping during summer), dissipating heat (for example through the long ears of Jackrabbits), being nocturnal, sitting in the shade, etc.