Thanks guys...
Is there a difference between the open cell and closed cell type pads though and the way that they insulate?
Closed cell pads hold the air in tiny bubblelike structures thus there is no convection flow of heat through the pad.
A typical air mattress with the big tubes does have a lot of heat loss to the ground through convection. A closed cell pad like the Z-rest or Ridgerest will insulate pretty well and the blowup pad on top will give something like soft comfort. On really cold snow a second closed cell pad will help a lot especially under your tent or ground cloth.
