Mass. Gen. Laws ch. 126 § 26
If disease breaks out in a jail or other county prison, which, in the opinion of the inspectors of the prison, may endanger the lives or health of the prisoners to such a degree as to render their removal necessary, the inspectors may designate in writing a suitable place within the same county, or any prison in a contiguous county, as a place of confinement for such prisoners. Such designation, having been filed with the clerk of the superior court, shall be a sufficient authority for the sheriff, jailer, superintendent or keeper to remove all prisoners in his custody to the place designated, and there to confine them until they can safely be returned to the place whence they were removed. Any place to which the prisoners are so removed shall during their imprisonment therein be deemed a prison of the county where they were originally confined, but they shall be under the care, government and direction of the officers of the county where they are confined.
Mass. Gen. Laws ch. 126, § 26