Any, or all, male prisoners confined in the county jail under Judgment of conviction of a misdemeanor, may be compelled to labor upon the public grounds or buildings of the county or upon the public roads in the county as hereinafter provided; provided, however, that no prisoner shall be compelled to so labor who may be physically unable to do so, or whose safekeeping may be endangered thereby, the question of exemption from such labor for either of the causes mentioned to be determined by the sheriff of the county.
(Prior code § 15.1)