I find my Xtherm good to go to about 10-ish degrees, if the temps are likely to dip below that I add a thin closed cell foam pad (I have various thicknesses 1/8-1/2", so can bring more pad if it's really frigid)
there is some good scientific debate on whether to put the ccf pad on top or under (most of it leaning on top), I usually put mine under- more piece of mind on sharp things poking the inflatable
there is some good scientific debate on whether to put the ccf pad on top or under (most of it leaning on top), I usually put mine under- more piece of mind on sharp things poking the inflatable