I burned the slash and trees from about 4 miles of freeway right of way about 27? years ago. I was working for Scarsella and had this rickety Cat 225 excavator and 4 honda powered fans. I'd work on 3 fires a day, and have them reduced to a pile of embers by the end of the shift.
I learned about personal limitations for extreme heat exposure, and that the bigger the excavator the better. A 400 would have been a better choice

You would think that the searing heat on your face would be it, or maybe on your hands on the controls. Nope.
It was nipples getting burned by the T-shirt that made me spin and track away from the heat.