If you would prefer instead to keep physical and mental conditions separate, double the number of boxes on each. That said, there is a cutoff: if two boxes total are marked on either condition in a row, no more boxes may be marked on that row. So if you had one box (out of two) marked on Hurt and none on Scared, and then marked either the second Hurt box or first Scared box, you would no longer be able to mark any more boxes on that row.

If you would gain a mild consequence slot (from high Physique, Will, or a stunt), instead add two more boxes of Hurt or Scared as appropriate. These added boxes increase the cutoff threshold for that row, one for one.