If you drop a large plastic bottle full of frozen drink onto a fire it melts (and the plastic bottle becomes burnt). If you try the same trick with a raging fire the bottle instantly burns away and the contents spill out. But if you do the same thing with an aluminium can nothing seems to happen, even if you wait 10 minutes. I’ve also had a pile of frozen stuff sitting next to this fire for a while without noticing anything melting.
carton’s of milk are also immortal