It's the other way around for me. At the Dream Cruise last year, temps were mid to upper 90s and after extended idling in gear in standstill traffic, the temp light would flicker a little. As soon as I was able to move, even a little, or shifted to neutral, the light would go off. After a few hours of this type of abuse, the light stayed on a little longer and I pulled into a lot to check it out. IR thermometer showed upper tank temps at 210 and there was no coolant odor or boilover, so I just hit the trigger point of the coolant sensor.

I have used the heat-on, windows open method after breaking a fan belt and having to make it just a little farther to stop in a safe location. I'm sure it doesn't hurt, but it is nowhere near as efficient as a 19", 7 blade clutch fan.