Yes, Si, Da, Ya.  Just to be clear: yes,yes,yes, absolutely yes!
Hot air rises and temperature stratification in a sauna is significant (10-15 degrees per foot).  if sitting on a single tier bench, you will not feel any heat.
That is why virtually all saunas have two levels of benches.  The bottom bench is really a step up and a foot rest.
It is for this reason that Saunafin also favors top tier L bench returns.