Hospitals typically have internal intercom codes used for situations when someone has suffered a cardiac arrest or a similar potentially fatal condition outside of the emergency department or intensive care unit (where such conditions already happen frequently and do not require special announcements). When such codes are given, hospital staff and volunteers are expected to clear the corridors, and to direct visitors to stand aside as the crash cart and a team of physicians, pharmacists and nurses may come through at any moment. (See Code Blue.)