Is sleeping on a yoga mat better than on an airbed during winter camping?
This is a follow up on question that my friend asked earlier, but I can't comment on. My friend and I have an ongoing argument about a question :
During cold winter camping (-20C air temperature, ground has more than 20cm of snow thickness, in a regular summer tent that has a thin soft floor) my friend slept on a regular uninsulated airbed and I slept on a yoga mat. We both had similar sleeping bags.
I had a relatively comfortable night of sleep, my friend got very cold.
I believe that his choice of sleeping on a thick airbed filled with cold air was the main reason why he felt more cold than I did, since his mattress is so big that his body could never heat up the air inside. He disagrees and believes the air in the mattress acted as insulator that protected him from the ground cold.
Who is right, and why?