The industrial appeals judge may, when all parties have rested, present such evidence, in addition to that presented by the parties, as deemed necessary to decide the appeal fairly and equitably, and in the exercise of this power, a physical, mental or vocational examination or evaluation of a worker by one or more medical or vocational experts may be ordered to be conducted at the board's expense. Any such evidence secured and presented by the industrial appeals judge shall be presented in an impartial manner, and shall be received subject to full opportunity for cross-examination by all parties. If a party desires to present rebuttal evidence to any evidence so presented by the industrial appeals judge, the party shall make application immediately following the conclusion of such evidence.