Hi Paul;
Well that depends on what type of
RMH we are talking about.
A brick bell can be extremely nice with a wooden chair almost touching it.
A comfy chair a foot away would be fine.
A piped mass RMH using a single barrel might get a bit warm a foot away from the barrel.
Anyplace else along the mass temps average around 100F or so.
With a batchbox RMH if you use a metal door you cannot put any chairs close to the front at all!
The metal Dragontech doors on my batchboxes average 400-500F so bunches of radiant heat near them.
My shop stove has a wooden chair that lives inches from the bell.
It is a favorite spot for customers to sit and chat while I work!