A Man, Shipwrecked at Sea, Spends 12 Hours Floating in the Ocean

Essay

A man, shipwrecked at sea, spends 12 hours floating in the ocean before washing up on the shore of a deserted island. This man's core body temperature has decreased due to the many hours spent in the cold ocean water, and he needs to warm up once he reaches the island. Here are two options for warming up:
Option 1: Siting on black rocks in the direct sunlight.
Option 2: Sheltering under a dense tree and using dry leaves as insulation.
Describe three different conditions in which sheltering under the dry leaves would provide more opportunity for heating up than sitting on the black rocks.