I recently made an UQ with Climashield that is rated for 40*. I have used it in temperatures in that range and could tell that 40* was an accurate representation of the limit of the insulation. Last night I decided to hang in the backyard to see if adding a pad would actually increase the insulative capabilities of the system. I had some sheets of 1/8" white insulation normally used for protective packing of computer and appliances that I slid into the pad sleeve in the hammock. I used my 20* mummy sleeping bag as a TQ. The temps got down into the low 30s last night and I had no problem with being cold at all. I did notice that there was some sweat on the hammock this morning, but apparently not enough to rob me of any BTUs.