Answer:
I am the key that is the hardest to turn
I am a million peopleβs wakeup call
I go through a door but never go in and never come out.
I am a shiny metal sheet that covers BBQ food.
I may be made of metal bone or wood and have many teeth. My bite hurts no one and the ladies love me.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?