Section 15. Such temporary guardian shall, until otherwise ordered, or until his removal or the appointment of a permanent guardian, have the same powers and duties relative to the person and estate of the ward as permanent guardians, and may be decreed the custody of the person of a minor, if the court finds the parent or parents unfit therefor or if it finds one of them unfit therefor and the other consents to such custody by the temporary guardian or if a temporary guardian is serving or appointed to serve in place of a temporary guardian removed. If such temporary guardian of a minor is appointed pending proceedings for an order for custody under section five or for the removal of a guardian of a minor, he shall have the sole custody and control of the ward during the pendency of such proceedings. Upon the termination of his powers, a temporary guardian shall deliver to the guardian or such person as is otherwise lawfully authorized to receive it the estate of the ward in his hands. A guardian may be admitted to prosecute an action commenced by a temporary guardian.