Everything else being equal, will you be warmest
a) Sleeping on the floor?
b) Sleeping on a mattress on the floor?
c) Sleeping on a mattress on a bed?
I've tried all three. I think most will agree b) beats a). But what about c) versus b)?
I felt warmer, and explained this by the air between the bottom of the mattress and the floor being a thermal layer.
However a friend disagrees (strongly). In their view the air gap between mattress and floor makes no difference. Any warmth that percolates down from my body to the air layer below will simply flow out the sides, and so only the mattress sits between me and the temperature of the floor.
Who is right in this heated debate? Can anyone comment?