I stopped combining wheat with my R7 today, as it is close to 40 celcius (103 F) and the temp guage was "flirting" with the red zone. Had an air conditioning thermometer handy, so I took temperatures in the engine compartment, both on the floor of the compartment( as well as 1' in the air). Metal was over 58 C or 130-135 F. Metal that was uncomfortable to touch (in my observation) was around 120 F or 50 C. Hope that helps. David