I've seen that thread with the dual setup as well. Wow that was a long time ago. I was thinking more of using the thermister so at a certain temp, or in this case resistance it would light a diode. Even a series of LED's each with a different value fixed resistor. This way as the temp rises another LED lights up. One would have to gather some data (resistance versus temp) so you know when the last LED lights up then something has gone wrong.

A small flow detector woud work too, but since the IAT sensor was fresh on my mind that's where I went first.

It just seems to be bad idea to run an IC without knowing whether the fliud is moving, or at minimum that said fliud is not going above a certain threshold.