What usually happens to me when i nap, is i start in in a nice warm sunny spot, and then as the sun moves, i end up in the shade. I awake cold and shivering. This napping mostly happened quite a long time ago. These days, what with global warming, it is usually too cold, and snowy in the mountains. One good thing, beins how i am retired, i am more rested when i hunt, so don't so strongly feel the need for a nap.