Also known as a ''Cilice'', Hairshirts were a form of Penitent garment worn by both Religious and Lay Persons. They were common throughout The Medieval Era and worn as a means of ''repentance'' of Sins. Hairshirts fall into the category of ''self mortification'', or the practice of creating pain or discomfort to ''atone before God''.
Hairshirts could be made from animal air or Coarse (a common Medieval cloth worn by Commoners). Another popular type was Sackcloth (which had a more Biblical application). Fashioned into a type of Shirt (or Vest), the hair or irritant was sewn into the inside of the holding fabric. It was often form fitting.
As one would expect, prolonged wear (especially in hot weather), cause great discomfort against bare skin. It was meant to be so, to provide a reminder of One's Sins. Normally, The Hairshirt was only worn for several hours, although some Aspirants ''suffered'' longer. Although currently not a common form of Penance in general usage, some Catholic Religious and Lay Orders still use variations.