There are many circumstances when a health professional is presented with an emergency situation, for example a patient brought into accident and emergency following a road traffic accident or heart attack or during an operation when something unexpected and life threatening occurs. When a health professional has to act in a situation where an emergency arises and it is not possible to find out a patient's wishes, the health professional can treat the patient without their consent. The health professional provided the treatment is immediately necessary to save their life or to prevent a serious deterioration of their condition. The health professional must take into account any advance statement as to their wishes. The health professional should only carry out necessary care or treatment until the patient's capacity returns. If the patient regains capacity they should be told what has been done, and why, as soon as they are sufficiently recovered to understand.