Mass. Gen. Laws ch. 215 § 6C
Upon a complaint, after a judgment pursuant to this chapter relative to the care and custody of minor children, filed by either parent or by a next friend on behalf of the children, after notice to both parents, the court may make a judgment modifying its earlier judgment as to the care and custody of said minor children provided that the court finds that a material and substantial change in the circumstances of the parties has occurred and that a modification is necessary in the best interests of the children.
During the pendency of such an action, upon motion of either party or of a next friend on behalf of the minor children of the parties and notice to the other party or parties, the court may make temporary orders relative to the care and custody of such children. Every order entered shall include specific findings of fact made by the court which clearly demonstrate the injury, harm or damage that might reasonably be expected to occur if relief pending a judgment of modification is not granted. An order entered pursuant to this section may only be entered without advance notice if the court finds that an emergency exists, the nature of which requires the court to act before the opposing party or parties can be heard in opposition. In all such cases, such order shall be for a period not to exceed five days and written notice of the issuance of any such order and the reasons therefor shall be given to the opposing party or parties together with notice of the date, time and place that a hearing on the continuation of such order will be held.
Mass. Gen. Laws ch. 215, § 6C