That's true but depending on what coolant and how much pressure is on it most systems will not boil over until about 240-260 and some a lot higher, and most engines would end up shutting down from electronic safety's or just plain lock up. Because remember the under pressure the boiling point is raised.
But this actually happened about 2 weeks ago when I was having problems with my resivor, I say there wasn't a drop of coolant in it but in reality there had to be some in it, just none visible in the radiator or resivor. As long as I stayed moving the temp never got over 3 bars, but at a stop light it would shoot up fan kick on but no change in temp. Even though the gauge might not have been reading 100% accurate at the time I'm positive the oil never got above that critical temp, whatever it might be. I have overheated it once while out in the shop and the check engine light came on and if you tried to rev it it just would not rev.
So in other words, sitting still=easy to over heat but if moving at a steady pace=almost impossible to over heat, a big almost, if the conditions are right I'm sure it would though
And yeah the 1-800 hotline has me on there most wanted list :BLAA: LOL