The World Federation One Stop Fiqh

Ruling 324

If a wound, boil, or broken bone is on one’s face or arms, and it is uncovered, and pouring water over it is harmful, then the area around the wound or boil must be washed from top to bottom in the manner that was explained regarding  wuḍūʾ. If drawing a wet hand over it is not harmful, it is better that one draw a wet hand over it, place a pure cloth over it, and then draw a wet hand over the cloth as well. As for the case of a broken bone, it is necessary to perform tayammum [instead of jabīrah wuḍūʾ].