Any member retired for disability as authorized in this article may be summoned before the State Board at any time to submit himself or herself to the State Board or some physician licensed by this state and selected by the State Board, to be examined as to the member's fitness for duty, and if found to be able to return to duty by the State Board, the member shall not be entitled to any further money from the funds of the System. All such members so retired as authorized under this article shall report, upon order of the State Board, to some physician licensed by this state and designated by the State Board, for an examination as to the member's fitness for duty, and if at such time the member be found fit for duty by the State Board, the member shall not be entitled to any further money from the System. In case of great public emergency any such member retired for disability may be assigned to and shall perform such duty as the Chief of the Police Department of the municipality may direct and such member shall not be entitled to any pay from the municipality for the duty so performed.