[07 Boss]

It's getting hot here in Vegas and had a couple of questions regarding setting the parameters for the cooling fans. My Diablo has 5 parameters that you can adjust. The low speed on and low speed off I think I understand. If my understanding is correct the low speed fan turns on where I set it and then I should have the low speed off set where the High speed fan comes on, right? Here comes the part that I really don't understand. The first 2 options say: High Speed Fan ECT 1 On & High Speed Fan ECT 2 On. What is the difference between the 2 settings? And then there is a High Speed Fan Off, where should this be set and why? Shouldn't the high speed fan stay on until the temp drops below the on parameter I set? Just a little paranoid with this being my first summer in the high desert with this car.