I remember seeing a video about melting ice on metal and wood blocks years ago and being simply amazed, and I love the next step that Inspiration Laboratories takes on it. Especially with a Wintery slant.
This would be so achievable in a STEM session, or fun end of term lesson, especially if you then took the worst surface and added salt, rock salt, other harmless white chemical and then compared with surfaces. For example, if metal is the best, can a chemical on a wooden surface make it better than metal?
Could you find enough stones, or a house brick, a paving slab, something akin to tarmac and test “outdoor” surfaces?