the present invention relates to an apparatus and method for a proximity warning system that is designed for use in warehouses , wharves , factories , and other industrial sites . the invention provides a proximity warning apparatus for use in warehouses , wharves and other industrial sites , comprising , a first transmitting and receiving means arranged to be mounted to a first body and to a second transmitting and receiving means arranged to be mounted to a second body , wherein the first and second bodies are movable relative to one another , so that they may come into proximity with one another and , wherein the first transmitting and receiving means is arranged to transmit a electromagnetic signal to the second transmitting and receiving means and vice versa , to provide an indication when the first and second bodies are in proximity to each other , or to provide an indication when the second and first bodies are in proximity to each other respectively .