Why do you have to stay in your tree stand all day long? I drive out to the deer hunting ground early, hunt the morning, go back to the house (about 20 miles away), return for the afternoon hunt, and then go back to the house. If I didn't want to waste gas, I think I would return to my truck and sleep about four hours in the middle part of the day. If you don't want to leave your stand area, I would climb down out of the stand and sleep on the ground. I think this makes a lot of sense unless you think the middle part of the day is a time the deer will be moving. It could happen, but in my experience deer bed down and move around precious little in the middle of the day. If bucks are in the rut that could be an exception -- I guess it depends on how your season falls.