Yeah, I think it will help. I'm weighing up a hexayurt vs using a big shade struct with reflective tarp over a tent + blanket as described. Both would be fed by a swamp cooler, probably a scaled up version of Figjam's http://www.instructables.com/id/Figjams-Swamp-Cooler/. I guess it's hard to get th...

I wonder whether additional thermal insulation of a tent under shade cloth would be useful?

e.g. a tent covered by a blanket with cheap synthetic loft under a shade cloth, with air fed in from a swamp cooler, and a small exhaust at the top of the tent.