24 Then King Nebuchadnezzar leaped to his feet in amazement and asked his advisers, “Weren’t there three men that we tied up and threw into the fire?”
They replied, “Certainly, O king.”
25 He said, “Look! I see four men walking around in the fire, unbound and unharmed, and the fourth looks like a son of the gods.”
The King James version does the hermeneutic for you and says "Son of God" at the end of verse 25. Is that a per-incarnate Jesus there in the fire saying "Well done, my good and faithful servants, well done"?
We can't answer that with the facts at hand, but Jesus would be the leader in the clubhouse for the ID of the quartet-maker. It would give new meaning to Emmanuel, God with us, for God (or at least an angel) was there in the fire.