keep your head on a swivel

to stay alert and aware of your surroundings
حواست جمع باشه، بپا، مراقب باش

مراقب بودن, مواظب بودن

دور و بر رو به دقت پائیدن و زیر نظر داشتن،
Keep an eye around you
To be constantly moving your head left and right so that you do not miss anything approaching you from a blind spot