Answer:
I usually wear a yellow coat. I usually have a dark head. I make marks wherever I go.
What can be swallowed, But can also swallow you?
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.
It is weightless, you can see it. If you put it in a barrel it will make it lighter?
They make no sense at all, In them you either fly or fall. They make you do it all. Their need is biologic, but they are most illogic. They are not real but still can be achieved, If they are just believed
In your fire you hear me scream! Creaking and whining yet I am dead before you lay me in your hearth.