My company used to operate a C310 off dirt and grass strips... some of them fairly rough. It coped very well and we had no issues. It can haul the same load as a C206 but obviously at a higher speed and commensurately greater cost.
How hot are we talking? The strips we were operating from would get to around 45 degrees in the hot season but it is a very dry heat - no humidity to reduce air density even further.