N.H. Rev. Stat. Ann. § 383:2

In case of temporary disability of the commissioner, or of a vacancy in the office, and there is no deputy commissioner, the governor, with the advice and consent of the council, may appoint a bank commissioner for the time being, who shall have the powers and perform the duties of the office while the disability continues or until another commissioner is appointed and qualified. The governor and council shall determine when such appointee shall cease to act.