According to the Croatian knitter Radmila Kus, knitted protectors were traditionally worn by Croatian men, particularly in the Mrkopalj mountain region, as a guard against frostbite. Such garments were also worn in Norway, where they were called forhyse, vænakot, or suspensorium. Several examples are preserved in the Norwegian Museum of Cultural History. Sometimes in Norway they would be made from squirrel fur with the fur side inside, to be worn under leather trousers in the winter. On the Faroe Islands such garments are called “kallvøttur” (man mitten) or “purrivøttur” (testicles mitten). There was a tradition in Norway and Denmark, particularly on the Faroe Islands, where a girl would present her boyfriend with a forhyse to see how seriously he took their relationship. If the gift was rejected, this was seen as evidence that he was not yet ready for marriage.
In modern culture
Since the 20th century, willy warmers are usually made as novelties and joke gifts rather than to serve a functional purpose. In 1939, while filming Gone with the Wind, Clark Gable received a present of a hand-knitted genitalia warmer from Carole Lombard. In the 1950s Joan Crawford knitted a "cock sock" as a parting present for Porfirio Rubirosa.
Dawn Steel, while working as a merchandiser for Penthouse in the early 1970s, found hand-knitted "cock socks" in Frankfurt, and subsequently secured the rights to market "extra large" red, blue and white versions through the magazine. By the early 1980s, the seaside resort Blackpool had willy warmers displayed alongside other merchandise in gift shops just outside the Pleasure Beach, where they were seen as reflecting the limit of sexually suggestive material which was considered permissible to display publicly. It was claimed in 1991 that Charles, Prince of Wales, received a green knitted warmer one Christmas, which was stored with other unusual gifts in the cellar at Highgrove House.
In male nude photography, as published in magazines such as Playgirl, cock socks have become a humorous substitute for the fig leaf, deliberately focusing attention upon the area concealed. In 1990-1, during the Gulf War, the British tabloid newspaper The Sun printed a pattern for a willy warmer, which it encouraged women readers to knit and send to soldiers in the Gulf. Early 21st century willy warmers are often made to represent religious or political themes, or in the form of animals. For example, in 2004 Ann Summers offered a horse's head design with a neighing speaker. British reality TV star Bobby-Cole Norris has repeatedly made headlines for his choice of willy warmers as swimwear, including both a simple pouch and an anatomically correct variety.
- Moore, Sally (1991). The definitive Diana : an intimate look at the Princess of Wales from A to Z. Chicago: Contemporary Books. p. 390. ISBN 978-0-8092-3948-1.
- Molloy, Mark (29 March 2012). "Croatian woman making a fortune from made-to-measure penis warmers". The Metro. Retrieved 30 March 2013.
- "Suspensorium from the Norsk Folkemuseum". Digitalt Museum. Retrieved 30 March 2013.
- Norsk folkemuseum (1960). "By og bygd". By og bygd. I hoveakommisjon, J. G. Tanum. 13: 68, 71, 74.
- Joensen, Jóan Pauli (2003). I ærlige brudefolk : bryllup på Færøerne. København: Museum Tusculanums forl. p. 40. ISBN 9788772898087.
- "Diary: Willy warmers prove unpalatable at WACL". PRWeek (originally published on www.campaignlive.co.uk). 19 November 2004. Retrieved 30 March 2013.
- Flamini, Roland (1975). Scarlett, Rhett, and a cast of thousands : the filming of Gone with the wind (4. print. ed.). New York: Macmillan. p. 225. ISBN 978-0-02-538670-9.
- Considine, Shaun (1990). Bette & Joan : the divine feud. New York: Dell. p. 275. ISBN 978-0-440-20776-4.
- Sloman, Toby (24 December 1997). "Obituary: Dawn Steel". The Independent. Retrieved 30 March 2013.
- Dick, Bernard F. (1997). City of dreams the making and remaking of Universal Pictures. Lexington, Ky.: University Press of Kentucky. p. 3. ISBN 978-0-8131-7004-6.
- Abramowitz, Rachel (2000). Is that a gun in your pocket? : the truth about female power in Hollywood. New York: Random House. p. 233. ISBN 978-0-375-75869-0.
- Jameson, Fredric (1983). Formations of pleasure (1. publ. ed.). London: Routledge & Kegan Paul. pp. 136, 139. ISBN 978-0-7100-9359-2.
- Schwenger, Peter (1984). Phallic critiques : masculinity and twentieth-century literature (1. publ. ed.). London: Routledge & Kegan Paul. p. 71–72. ISBN 978-0-7102-0164-5.
- "The War in Croatia through the Prism of Human Rights". Peace Psychology Review. 1 (1–2): 26. 1994. Retrieved 30 March 2013.
- Mau, Dhani (16 April 2012). "Rock out with your Cock Out: Penis Warmers are now a Thing". Fashionista.com. Retrieved 30 March 2013.
- Rees, Alex (September 25, 2014). "Again, You Will NEVER Be Able to Unsee This Guy's Insane Bathing Suit". Cosmopolitan. Retrieved August 14, 2017.
- Campbell, Tina (February 10, 2015). "Forget the Schlong Thong, Bobby Cole Norris rocks a penis sock". Metro. Retrieved August 14, 2017.