Telegraph: I am in Melbourne, with its terrifying fires, and the tragic human costs that emerge from them. In Britain, we complain about cold, but warmth is much more dangerous — not just because of the flames, but because we, like all forms of life, live closer to heat death than to frostbite. This week’s frightening events remind us of that, and of the importance of subtle rules of chemistry to our survival. Drop an ice cube on to a Melbourne pavement, and it melts and then evaporates. The …