(A) If the mayor is temporarily absent because of an incapacity to perform official duties, but the incapacity does not create a vacancy in the office, the city council shall elect one of their members to act as mayor or mayor pro tem. The mayor pro tem, during this absence or disability, shall perform the duties and possess all the rights and powers of the mayor but shall not be entitled to vote both as mayor pro tem and as alderman or trustee.
(B) In the absence of the mayor, acting mayor, acting mayor or mayor pro tem, the city council may elect one of their members to act as temporary chairman. The temporary chairman shall have only the powers of a presiding officer and a right to vote only in the capacity as alderman or trustee on any ordinance, resolution, or motion.
(ILCS Ch. 65, Act 5, § 3.1-35-35) ('69 Code, § 2-24)