Making A Warmer Truck Camper Bed

We are actually headed to North Dakota. In researching reflectix we found that by itself it’s r value was 1. By adding air space of about 1/4 inch it increases to 3. We put corrugated cardboard and reflectix under our mattress and it works great. + whatever number were on for the heated mattress pad. Add a down comforter and a wool blanket. You will sleep toasty warm. We generally turn our heat down to 60 at night and sleep well. Safe and comfy travels to all.