Doctors may not impose treatment without a patient's fully informed consent, except in special circumstances permitted by law, for example emergency life-saving treatment when the patient is unconscious. In the UK, the GENERAL MEDICAL COUNCIL (GMC) requires that consent must be fully informed, that is the patient must have been given a proper opportunity to know the facts about the proposed treatment or investigation, including risks and benefits and there must be no coercion by the clinician, who must be satisfied the patient understands the details and implications of what is proposed. Patients can give consent orally or in writing, or they may imply consent by complying with the proposed examination or treatment, for example, by rolling up their sleeve to have their blood pressure taken. However, in any situation that involves risk, written consent is the rule. By law, in the UK, doctors must have written consent for certain treatments, such as fertility treatment and must follow the laws and codes of practice that govern these situations.