Answer:
I make you weak at the worst of all times. I keep you safe, I keep you fine. I make your hands sweat. And your heart grow cold. I visit the weak, but seldom the bold.
Everyone has it and no one can lose it, what is it?
Covered in stone and sun. It's home to many but also none. What is it?
What has 4 legs in the morning, 2 legs in the evening and 3 legs in the night?
My head bobs lazily in the sun. You think I'm cute. For my face is yellow my hair is white and my body is green.
You use it between your head and your toes, the more it works the thinner it grows.