Das ist der Weg.

If it reflects signals on the outside it reflects signals on the inside.

On the outside the signals will be reflected away from you. On the inside the signals now reflect around inside hat and inside your head until they get out or are fully absorbed by your head.

You need to fully cover the face for better protection. Maybe don’t cut eye, nose, or mouth holes if you want to be safer. Better yet, sever your head at the neck and then you can cover all sides, making sure no signals can get in at all.