Large animals inhabit the desert have evolved adaptations for reducing the effects of extreme hot. One adaptation is to be light in color, and to reflect the Sun's rays. Desert mammals also depart from the normal mammalian practice of maintaining a constantly body temperature. Instead of try to keep down the body temperature inside the body, what would involve the expenditure of water and energy, desert mammals allow their temperatures rise to what would normally be fever height, and temperatures as high as 46 degree Celsius have been measured in Grant's gazelles. The overheated body cools down during the cold desert night, and indeed the temperature may fall unusual low by dawn, as low as 34 degrees Celsius in the camel. This is a advantage since the heat of the first few hours of daylight absorb in warming up the body.