The Secretary may act in the place and stead of a judge in any proceeding herein. When the Secretary so acts, the hearing clerk shall transmit the record to the Secretary at the expiration of the period provided for the filing of proposed findings of fact, conclusions, and orders, and the Secretary shall then, after due consideration of the record, issue the final decision in the proceeding: Except the Secretary may issue a tentative decision in which event the parties shall be afforded an opportunity to file exceptions before the issuance of the final decision.