The surface is heated by the Sun and some of that heat radiates back into the air. This makes the temperature higher near the surface than at higher altitudes.  Devon's cat, Fluffy, is looking for a nice warm spot to lay out in the sun. Because of how the sun heats the earth, and how some heat radiates into the air, the cat laying on the ground, rather than high up in a tree branch, would keep the cat cooler or warmer?
The answer to this question is:
warmer