53 Pa. C.S. § 1122
Whenever, due to an emergency resulting from the effects of enemy attack or the anticipated effects of a threatened enemy attack, it becomes imprudent, inexpedient or impossible to conduct the affairs of local government at the regular or usual place, the governing body of each political subdivision of this Commonwealth may meet at any place, within or without the territorial limits of the political subdivision. The meeting may be held on the call of the presiding officer or any two members of the governing body and shall proceed to establish and designate, by ordinance, resolution or other manner, alternate or substitute sites or places as the emergency temporary location or locations of government, where all or any part of the public business may be transacted and conducted during the emergency situation. These sites or places may be within or without the territorial limits of the political subdivision and may be within or without this Commonwealth.
53 Pa.C.S. § 1122