No mention of wet headcloths and neckerchiefs here! Get some water on that neckerchief and it’ll drip down the hotter parts of your body. A wet headcloth loosely draped under a hat or headband catches the wind and sends evaporative cooling down your back, and gives you cooler air to breathe.

There’s a reason why deserts around the world are filled with garments like the keffiyeh, pashmina, shemagh, pañuelo, and cowboy scarf. I’ve spent a lot of time in the outdoors with a kufiya from the Hirbawi factory in Palestine, they’re well-made and amazingly handy. Their story is worth reading at http://www.hirbawi.ps .

this is underground morlock burrow erasure

Yes. Foam or bubble wrap underneath the foil is best for performance over time, even just cardboard can be a meaningful improvement.