At 1400 in July, the weather is 105 degrees F and very humid. You have been called for a "man down" at the park. As you arrive, you recognize him as an alcoholic who has been a "frequent flyer" with your service. It looks like he had been sitting under a tree when he fell over, unconscious. The direct transfer of heat from his body to the cold ground is called:

a. conduction
b. convection
c. radiation
d. evaporation

Ans: a. conduction