Answer:
The higher I climb, the hotter I engage. I cannot escape from my crystal cage.
You use it between your head and your toes, the more it works the thinner it grows.
I always follow my brother but you cannot see me, only him. You cannot hear him but you can hear me. What are we?
I am nothing but holes tied to holes, yet am strong as iron.
What two things can always see what the other sees, but can never see each other?
What covers its face with its hands, speaks no language, yet most known what it's saying?