Hey Dave, I have two thermos in the floor and one is about a half inch below the surface. My thermos are rated for 1000F and I have had it read over a 1000 a few times and once 1035F. It is amazing the difference in temp between one near the surface and one just a couple of inches below. Of course I didn't figure that out. It was from that guy that just past 1000 posts....what's his name again? I am starting to think that his name is "thanks again Jim"
Cheers, John