Section 74A. Any governmental unit, which words as used in this section shall mean the commonwealth or any political subdivision thereof or any municipal gas or electric commission, may, by action of the executive or board having jurisdiction in the commonwealth, the county commissioners in a county, the mayor in a city, the board of selectmen in a town, or by the action of any other executive or board having jurisdiction, as the case may be, request and authorize any employee in its service to go to the aid of a second governmental unit or an electric company as defined in section one of chapter one hundred and sixty-four, if in the judgment of the head of the department in which such employee is regularly employed such action is necessary. Any electric company may go to the aid of any governmental unit or other electric company. While in the performance of his duties pursuant to such request and authorization, any such employee of the commonwealth and any county, city, town, or district having the power of taxation which has accepted chapter eight hundred and seven of the acts of nineteen hundred and thirteen, or any town or district having the power of taxation which has accepted or accepts the provisions of section sixty-nine, or any electric company shall be subject to the provisions of and shall be paid the compensation provided by this chapter, as if performing the same duties within the scope of his regular employment.

The governmental unit or electric company so requesting such assistance shall reimburse in full, in accordance with the provisions of this paragraph, the first governmental unit or electric company for any compensation payments lawfully made by it or on its behalf on account of any injuries suffered by such employee in the course of rendering such aid, or on account of his death as a result of such injuries. The treasurer of the first governmental unit or electric company shall annually, on or before January fifteenth, upon the certification of the compensation agent or the insurer furnishing the benefits due under sections sixty-nine to seventy-five, inclusive, notify the treasurer of the second governmental unit or requesting electric company of the amount of reimbursement due therefrom for the previous fiscal year, and such latter treasurer shall forthwith take such steps as may be necessary to insure prompt payment of such amount. All such payments due under the provisions of this paragraph from the second governmental unit or requesting electric company shall be paid by the insurer of the second governmental unit or requesting electric company, or if such governmental unit or electric company has not provided for payment of compensation by insurance with an insurer, then they shall be paid by the requesting electric company or by such governmental unit from a special appropriation, or from an insurance fund established under section thirteen A of chapter forty, and as received they shall be credited to the insurer of the governmental unit which made the payments. On default of any such payment, the first governmental unit or electric company may maintain an action of contract to recover the same.