Whenever the necessity arises (i) for the enforcement of laws designed to control or prohibit the use or sale of controlled drugs as defined in § 54.1-3401 or laws contained in Article 3 (§ 18.2-47 et seq.) of Chapter 4 or Article 3 (§ 18.2-346 et seq.) of Chapter 8 of Title 18.2, (ii) in response to any law-enforcement emergency involving any immediate threat to life or public safety, (iii) during the execution of the provisions of Article 4 (§ 37.2-808 et seq.) of Chapter 8 of Title 37.2 or § 16.1-340 or 16.1-340.1 relating to orders for temporary detention or emergency custody for mental health evaluation or (iv) during any emergency resulting from the existence of a state of war, internal disorder, or fire, flood, epidemic or other public disaster, the police officers and other officers, agents and employees of any locality, the police officers of the Division of Capitol Police, and the police of any state-supported institution of higher learning appointed pursuant to subsection B of § 23.1-812 may, together with all necessary equipment, lawfully go or be sent beyond the territorial limits of such locality, such agency, or such state-supported institution of higher learning to any point within or without the Commonwealth to assist in meeting such emergency or need, or while en route to a part of the jurisdiction which is only accessible by roads outside the jurisdiction. However, the police of any state-supported institution of higher learning may be sent only to a locality within the Commonwealth, or locality outside the Commonwealth, whose boundaries are contiguous with the locality in which such institution is located. No member of a police force of any state-supported institution of higher learning shall be sent beyond the territorial limits of the locality in which such institution is located unless such member has met the requirements established by the Department of Criminal Justice Services as provided in clause (i) of subdivision 2 of § 9.1-102. In such event the acts performed for such purpose by such police officers or other officers, agents or employees and the expenditures made for such purpose by such locality, such agency, or a state-supported institution of higher learning shall be deemed conclusively to be for a public and governmental purpose, and all of the immunities from liability enjoyed by a locality, agency, or a state-supported institution of higher learning when acting through its police officers or other officers, agents or employees for a public or governmental purpose within its territorial limits shall be enjoyed by it to the same extent when such locality, agency, or a state-supported institution of higher learning within the Commonwealth is so acting, under this section or under other lawful authority, beyond its territorial limits. The police officers and other officers, agents and employees of any locality, agency, or a state-supported institution of higher learning when acting hereunder or under other lawful authority beyond the territorial limits of such locality, agency, or such state-supported institution of higher learning shall have all of the immunities from liability and exemptions from laws, ordinances and regulations and shall have all of the pension, relief, disability, workers’ compensation and other benefits enjoyed by them while performing their respective duties within the territorial limits of such locality, agency, or such state-supported institution of higher learning.