The Council shall, at its first regular meeting following each regular biennial City election, select one of its members to serve as Mayor Pro Tem. The Mayor Pro Tem shall perform the duties of the Mayor when, on account of absence from the City, disability or otherwise, the Mayor is temporarily unable to perform the duties of his office, and, in case of vacancy in the office of Mayor, until such vacancy is filled by the Council. In the event of a vacancy occurring in the office of Mayor Pro Tem, the Council shall appoint from its membership to fill such vacancy and, in the time of emergency, members of the Council may act as Mayor Pro Tem in the order of the number of votes received by them at their election, until a Mayor Pro Tem is so appointed.