check if empty game object is colliding

How do i check if an empty game object is colliding with an object?

I added a empty game object to the top of my players head to see when he hits the ceiling, because he floats for a bit when he jumps and hits it. I need to limit his jump when he hits his head. does this make sense?

does this make sense? : Yes and No

Yes, because if you pretend to detect something over the characters head, you must place there a “detector·”. No because you need more than a empty object. You need a trigger collider and a script (using OnTriggerStay), so is not empty anymore.