Front defroster. In order to help dry the air going onto the windshield, the factory programmed the engine controller to turn on the ac system.
This turns on the electric fan at the radiator that helps cool the radiator.
Trust me, dependent on the plow and speed, finding that sweet spot is tough. A balancing act for sure. But I found dropping the speeds when you can and heater on full blast also helps. I’ve even had days where racing to the next parking lot (customer is crying) I’ve had to open the windows (while snowing) and raise the heat to drop engine temps. Also watch your transmission temps. Don’t let it go over 180. Plowing and pushing snow raises that very quickly. Driving with the blade on just as quick. Good luck!
Syleng1