Burn bin help

I was going to use a burning bin like this one.

But last time I used it to bottom got hot and burn my grass. I was thinking of put it on a pallet like this one would it be ok

 

I would think the wood will get hot too, smoulder then burn, have you nowhere to put a paving slab to stand it over.
I have mine over gravel. Unfortunately one year it was too close to the apple tree and I had some roasted apples.