For your edification, the account of Suso, a fourteenth-century German monk, as recounted by William James:
"He was in his youth of a temperament full of fire and life...and he sought by many devices how he might bring his body into subjugation. He wore for a long time a hair shirt and an iron chain, until the blood ran from him...He secretly had an undergarment made for him; and in the undergarment he had strips of leather fixed, into which a hundred and fifty brass nails were driven, pointed and filed sharp, and the points of the nails were turned always toward the flesh. In this he used to sleep at night.
Now in summer he would, when it was hot, and he was very tired and ill, and he lay thus in bonds and tormented by insects, cry aloud and give way to fretfulness...so he devised something further- two leather loops into which he put his hands, and fastened one on each side of his throat, so that even if his cell had been on fire he could not have helped himself.
This he continued until his arms had become almost tremulous with the strain, then he devised something else: two leather gloves, and a brazier between them, studded with sharp-pointed brass tacks, so that if he should try to throw off the hair undergarment, or relieve himself from the gnawing of the insects, the tacks might then stick into his body. So it came to pass. If ever he sought to help himself, he drove the sharp tacks into his breast, and tore himself, so that his flesh festered.
He continued this exercise for about sixteen years. At the end of this time a messenger of heaven came to tell him God required this of him no longer. Thus he took all these things and threw them into the running stream.
Then in imitation of Christ our Lord, he made himself a cross with thirty protruding iron needles and nails. This he bore on his bare back between his shoulders day and night. The first time that he stretched out this cross upon his back his slender frame was struck by the terror of it, and blunted the nails with a stone. But he then repented of this womanish cowardice and pointed them again with a file, and wore the cross once more.
It made his back, where the bones are, bloody and seared...if anyone touched him unawares, or pushed against his clothes, it tore him. For penitence he devised means of pushing the nails deeper in his flesh by striking the cross.
Also at this time he procured an old castaway door, and he used to lay upon it at night without any bedclothes...hard pea shalks lay in humps under his bed, his arms were locked fast in bonds, the horsehair undergarment was locked round his loins, and he sent up many a sigh to God.
In winter he suffered very much from the frost. If he stretched his feet out they lay bare on the floor and froze. If he gathered them up the blood became fire in his legs and this was exceedingly painful. His feet were full of sores, his legs dropsical, his knees bloody and seared, his loins covered with scars from the horsehair, his body wasted, his mouth parched with thirst, and his hands tremulous with weakness. All this he suffered for Christ our Lord.
It was also his custom, during these twenty five years...never to go after Compline in winter into any warm room, or to the convent stove to warm himself, no matter how cold he might be...Throughout all these years he never took a bath, either a water bath or a sweating bath, and this he did in order to mortify his comfort-seeking body. He practiced during this time such poverty that he would never receive nor touch a penny.
For a considerable time he strove to attain such a high degree of purity that he would neither scratch nor touch any part of his body, save his hands or feet.
It is pleasant to know that after his fortieth year, God conveyed to him through a series of visions that he had sufficiently broken down the natural man, that he might leave these exercises off."