What am I?

I climb higher as I get hotter. I can never escape from my crystal cage. What am I?

When people can control me, people love me. When people lose control of me, people fear me. I cast shadows, but have no shadow myself. What am I?

I can sing, but I can't talk. I can climb a high tree, but can't run. I have very soft hair and a very hard mouth. What am I?

I'm not at all heavy, but even the strongest man in the world can't hold me for long.

Riddles and Answers