A cooling structure and a method of cooling a surgical robot arm. The surgical robot arm extends from a proximal end attached to a base to a distal end attachable to a surgical instrument via a series of links interspersed by articulations. The cooling structure comprises a loop for circumscribing the surgical robot arm. The loop comprises a hollow interior for feeding cooling fluid through the loop, and a series of orifices directed towards the surgical robot arm for feeding cooling fluid from the loop towards the surgical robot arm. The cooling structure further comprises a feeder conduit attached to the loop for feeding cooling fluid from a cooling fluid source to the loop.