A light coupling assembly that couples a light source to a light conducting system attached to a medical instrument so that light from the light source is transmitted to a surgical site. The light coupling assembly according to the present invention includes a member formed of a heat conducting material that receives and transfers heat from the light source to a light source housing. The light coupling assembly also includes an insulating member that receives a portion of the heat conducting member and prevents an attendant from being injured by the heat generated by the light source and carried by the heat conducting member.