A surgical robotic arm drape 301 for enveloping a portion of a robotic arm 207, the drape comprising: an exterior sheet defining an elongate cavity for housing a portion of a robotic arm； and a duct 305 defined at least in part by material integral with the exterior sheet, the duct defining a fluid path along the longitudinal extent of the cavity to channel fluid to or from a robotic arm housed within the cavity. The duct may be a tube attached to the sheet, concentric with the sheet (see figure6), or material integral with the sheet (507, see figure 5). Alternative embodiments provide a surgical robot arm with surface features (1007, see figure 10) which cooperate with a surgical drape to form a duct for channelling fluid to or from the robotic arm； or longitudinal features on the surgical drape (507, 707, see figure 7B) which cooperate with a robot arm to form a duct. The duct may deliver cooling fluid to prevent overheating of the motors of the robotic arm joints.
