Have been using the BA Aircore for a few season, and poped a Termarest Neo Air a year before that. Both isulated. When the temp drops I noticed I get the chills. Have a Marmont Heluium bag. Then I tried putting my clothes between the mattress and my self. No more chills. I know, it makes sense!! Put something between you and a pad with air that gets as cold as the outside air, or sucks it up from the ground. Just wondered if any one else has noticed this.