An Emergency Room (ER, or Emergency Department or ED) is a specialized hospital area that deals specifically with acute injuries and illnesses. In this context, "acute" can mean anything from a cold to a cardiac arrest, but is generally means something that requires diagnosis and treatment that is not immediately available in a physician's office. Typically, an ED will have the ability to do x-rays and usually CT scans, the ability to analyze blood counts and blood chemistries, the ability to detect infections and the ability to stabilize fractures for later definitive treatment. Most ED's are required to be open 24 hours and (except in very rural areas), must have a physician and nurse available at all times. The ED should have the ability and arrangements in place to transfer a patient quickly to a higher level of care in another hospital if the ED's own hospital cannot handle the patient's problems.