[Nyororin]

I was always under the assumption that 冷える is something that just happens - but that 冷める is something that happens due to direct involvement of some factor.

It is a hard thing to explain... But if I were to talk about being cold, I would never use 冷める. It`s something that happens to things - like the previous example of the soup getting cold. But 冷える is more abstract, like "I`m cold", or "It`s cold outside."

Maybe like the difference between the all encompassing "cold" and "chilled". Chilled implies the direct temperature, while "cold" could have a variety of meanings.

Sorry I`m not more help. It is just one of those words that you know but can`t explain clearly.