Are you talking about sleeping on snow? If so, I have used my Exped DAM 9 by itself, a ThermaRest 3/4 LE, 1.5" thick with a 3/8" blue ccf pad and my NeoAir small with the blue ccf pad in the snow. One of my hips felt just a tiny bit cool when using the NeoAir/ccf pad over NY's in Yosemite, very insignificant though. In my experience, the small NeoAir on unfrozen ground is good into the mid single digits using a 15 degree down bag with a jacket draped over by morning. Did that two nights in a row. On frozen ground, may be a different matter. Per my two zip-o-gauges and the ice on slow moving water, I know it was cold.