I had to explain why that was funny to a colleague in Marketing. It seems STEM subjects are optional there. The simplest and easiest-to-understand analogue I could think of was by way of a question.
Would small ice cubes be a good way to stop a large volume of very hot water?
You could see the light bulb gradually turning-on.
But then, just to check, I did look it up, the melting point of concrete (depending on the mix) is c. 1527 °C
Whereas the temperature of lava is what? Oh dear, it turns out I'm not such a clever-clogs after all.
https://www.livescience.com/32643-how-hot-is-lava.html
It would have to be a small volcano (or perhaps far away?)