PEN § 1482

When, from sickness or infirmity of the person directed to be produced, he cannot, without danger, be brought before the Court or Judge, the person in whose custody or power he is may state that fact in his return to the writ, verifying the same by affidavit. If the Court or Judge is satisfied of the truth of such return, and the return to the writ is otherwise sufficient, the Court or Judge may proceed to decide on such return, and to dispose of the matter as if such party had been produced on the writ, or the hearing thereof may be adjourned until such party can be produced.