How does a kangaroo keep cool?

Aside from seeking shade and being inactive during the hottest parts of the day, they lick their forearms. Their arms have many veins that run very close to the surface of the skin, as the saliva evaporates in cools the blood and thus lowers their overall body temperature. Kangaroos, like many other animals, also dig off the top, hot, layer of sand to get to the cooler dirt underneath and lay down in that.