Beat the heat. learn from the animals, dogs dig holes to lay in because it's cooler the closer you get to the ground( if I remember correctly once you dig down around a foot deep the soil is close to 57-60 degrees F).This next one is said to be a health hazzard(snicker). Cigarette smoking cools the temp of your blood(I have always wonder about dipping tobaccoo) and it does impair your night vision. I quit 2 years ago and I believe this to be true. I actually see better at night and I'm warmer natured now.My hands, feet and ears don't get as cold either(I didn't wear gloves or a watch cap at all last winter).
It takes 8ft of foliage or 8in. of packed dirt(Think it's 8)to hide your IFR signature and if it will hide that, it will also keep you warm.
Don't wash your BDUs in detergent that has phosphrous(Tide is one) in it you will light up like a Christmas tree when viewed through NVDs or a blue light. Take a 1lb coffee can a board or rock stuff a chicken in the can and bury it sitting on the board in pine straw, light the pine straw by time it burns off the chicken is ready to eat. I don't remember how much pine straw you need to pile up. I tyred this and it works! It's from the U.S. Army survival manual.
Take a 33gal (black works best)trash bag, find a small tree or large bush. Bunch up several limbs, place a large rock in the bag, then tie it around(the bag) the limbs and it will make water to drink. Sunlight helps, I think they called this a condensation still.