I've seen this discussed as something to be avoided and have seen the impact of putting a very hot glass in the sink and having it come in touch with very cold water. Sometimes the glass breaks.
I've noticed my engine cooling rapidly at times and want to learn more. Is there more scientific data on shock cooling and its impact on engines? Is there a base rate of problems? Is there a certain time frame of concern, is it an instantaneous change as in the glass in the sink, or does over a minute or two really matter?
Yesterday I was 9500 VFR when my destination seemed to be going IFR. I turned around and the cloud picture ahead of me looked impressive. 20 miles out my options looked best if I could get beneath the clouds while I could, I did so, but it required some rapid descending. This cooled things down.
In addition to just wanting to learn, I am curious how others might manage their engines in such scenarios? I couldn't keep the temps up.
en.wikipedia.org