Originally Posted By: Arney

I wonder if two sheets with an air gap would be better than a single sheet, or simply stacking two sheets together? Top sheet heats up and heats the air between the sheets. That pocket of hot air rises and drifts up and away by convection. Also, the inner sheet may help block the heat that gets through the top sheet. Anyway, just a theory.



In the US army survival manual it recommends what you describe. Double layering the tarp material for a desert shelter with an open space (about 12') in between the layers. Supposedly it can reduce internal temps by 20-30 degF. Haven't tried it yet but I see no reason why it wouldn't work.