; (ii) a public health emergency; or (iii) a mass casualty event. (12) Rule of construction Nothing in this subsection shall be construed— (A) to limit the authority vested in the Attorney General by other provisions of this title to take measures to prevent diversion of controlled substances; or (B) to override the authority of any State to regulate the provision of emergency medical services consistent with this subsection. (13) Definitions In this section: (A) The term authorizing medical professional means an emergency or other physician, or another medical professional (including an advanced practice registered nurse or physician assistant) who is— (i) registered under this Act; (ii) acting within the scope of the registration; and (iii) whose scope of practice under a State license or certification includes the ability to provide verbal orders. (B) The term designated location means a location designated by an emergency medical services agency under paragraph (5). (C) The term emergency medical services means emergency medical response and emergency mobile medical services provided outside of a fixed medical facility. (D) The term emergency medical services agency means an organization providing emergency medical services, including such an organization that— (i) is governmental (including fire-based and hospital-based agencies), nongovernmental (including hospital-based agencies), private, or volunteer-based; (ii) provides emergency medical services by ground, air, or otherwise