What is a flame -- how would you describe it to an 11 year old? (flamechallenge.org)

I'd really like to hear Richard Feynman's answer. I'm sure if an 11 year old had asked the question, instead of a journalist, it would be the perfect answer. (I'm referring to an interview series with him: http://www.youtube.com/watch?v=N1pIYI5JQLE)

Makes me sad to think I will never meet this man, nor ever be as awesome.