any closed cell will save yer heat but at the cost of some comfort.
something like a themarest is more comfy most definitely but at the cost of several r values.
the warmest combo, which I use is a thermarest neo air and a closed cell [army surplus] on top of it.
I throw my Big Agnes insulated inflatable on my cot, along with an el cheapo sleeping bag, flannel up for a bottom sheet, then use my down quilt on top and sleep like a baby below freezing