Mike, if you are lucky you may have done what I did a long time ago. (I say that because I TRY to treat my stuff more carefully now. And my memory may be foggy.)

If lucky: you had localized freezing (ice) or slush or... and your coolant pump didn't circulate as well as it should, or some ice/slush clogged some passage.

If lucky: you then got localized heating, with some hot water and a high gauge. You stopped soon.

Finally, when the hot engine sat, it melted whatever localized ice/slush remained within, and when you started up again it seemed back to its peppery self.

I did it with a 1951 Jeep wagon. No cracks, no real harm, it seemed.
Knock on wood!
--
Gregg in MN