In Old English, the noun fever (febbr, feber, fefur) generally refers to a bodily temperature deemed “abnormally” high and caused by a pathological agent (OED, n.1, 1.a). The term originates partly from the Latin febris and is partly a borrowing from the French fevre. The Anglo-Norman fever, fevere, fevre, fevir, feivre and the Old French fievre further contribute to its etymology. Although the exact origins or the term are unknown, the OED explains that fever may come from the same Indo-European base as the Latin fovēre, which means “to heat.” The term’s association with diagnostically high body temperature continues in Middle English (febre, fefer, fefor, feofer, fovre, fevir, fiever, fiver, fifere, feuere, feuer). After the fourteenth century, the term is used figuratively to describe an agitated or anxious state. When used in its plural form (februm, feferum, feueres, feueris, febres), the term denotes recurring instances of high body temperature (OEDn.1, 1.b). Its intransitive verb form means “to become feverish, to be affected with a fever” (OED, v. 1.a). The Old English fevering (fefer3indum) describes one who is becoming or is affected by a fever (OED), while the Middle English feverish (feuerisch) describes anything “of, relating to, or arising from fever” (OED, 1.a).

Related terms


In its earliest uses, fever is used to describe an “unnatural” heat that harms the body as opposed to the “natural” temperature that preserves a body’s vitality. Galen’s On the Differences of Fevers  follows Hippocrates in presenting a detailed classification of the characteristics of fevers, noting the degree, manner (acute vs. chronic, continuous vs. intermittent or isolated, and simple vs. compound), and matter of a body’s “unnatural warmth” (Book 1, Chapter 1, qtd. in DeMaitre 35). Galen further differentiates the parts of the body a fever affects, forming a triple classification: “fevers which affect the spirits (pneumas); fevers which affect the liquid parts (humours); and fevers which affect the solid parts (organs)” (Peña Muñoz and Girón Irueste 97). A fever was marked by its duration and occurrence and could be viewed as a discreet malady as well as a symptom of other causes. As a result, there are a wide variety of terms and descriptors used to differentiate fevers. For instance, in Middle English “fever hectic” (fievre ethique) was “a prolonged, debilitating fever causing wasting of the body” that afflicted the organs, while a “fever lent” (fievre lente) was a “prolonged or low-grade fever” (OED, c.1). Fevers could be “quotidian” and peak daily, “biduan” and peak every other day, “tertian” and peak every third day, or “quartan” and peak every fourth day (Wallis 546). Indeed, Peña Muñoz and Girón Irueste distinguish and describe more than fifty types of fevers across three medical treatises that were widely used in the Middle Ages.

Galen, moreover, classified the causes of fevers, noting that most often they are caused by “physical and emotional condition of the patient, a miasma or ‘pestilential quality of the air,’ and an unhealthy lifestyle” (DeMaitre 42). Agents as various as humoural imbalance, unsanitary water conditions, changes in air temperature, ingesting hot food or drink, extreme emotions, and injury to the body causing broken skin are named as causes of fevers. Liam O. Purdon, who reads the excessive body heat of Chaucer’s Cook as a result of a fever induced by his infected sore (“mormal”), notes, “Medieval medical practitioners understood the connection between the condition of fever and various maladies or morbid physical conditions, especially inflammation, the reaction of tissues in sores to injurious agents, as in the instance of the ‘mormal’” (211).

Although early on fever is used to denote a pathological condition of the body, beginning in the fourteenth century, it is used figuratively to describe states of “intense nervous excitement or agitation” (OED, 2). People in these states, which were often caused by an emotional response to an object of erotic desire, would behave as if afflicted with a fever. As John Gower explains, “Love is a wofull blisse[…]A lusti fievere, a wounde softe” (Confessio Amantis, 5.5995) For example, John Lydgate asserts that Troilus, “For loue of Cryseyde […] he was shake with a feuere newe Þat causid him to be ful pale of hewe” (Troy Book, 3.4285). The expression blaunk fever was even used to name “a stage of lovesickness analogous to chills” (MED, 3.a)

Instances of fever in the bible reflect the pathological condition of the body and are associated with illness. Old Testament examples list fevers as an example of a divine punishment for sinful behavior (Deuteronomy 28:22 and 32:24). New Testament occurrences of fevers showcase the healing powers of Jesus, as when he heals Simon Peter’s wife of a fever (Matthew 8:14-15, Mark 1:31, Luke 4:38-9), and later Paul, who heals Publius’ father (Acts 28:8).

Evidence and Images

Bible Verses
Deuteronomy 28:22
Deuteronomy 32:24
Matthew 8:14-15
Mark 1:31
Luke 4:38-9
John 4:52
Acts 28:8

Bibliography and Further Reading

DeMaitre, Luke. Medieval Medicine: The Art of Healing from Head to Toe, Praeger, 2013.

Peña Muñoz, Carmen, and Fernando Girón Irueste, “The Identification of Medieval Fevers According to Al-Isra’ili, Avenzoar and Bernard Gordon,” Cronos, 8 (2005): 95-120.

Purdon, Liam O. “‘And of that drynke the Cook was wonder fayn’: A Reconsideration of Hogge of Ware’s Drunkenness,” The Chaucer Review, 52.2 (2017): 202-9.

Wallis, Faith, editor. Medieval Medicine: A Reader, University of Toronto Press, 2010.

Wright, William F. “Early Evolution of the Thermometer and Application to Clinical Medicine,” Journal of Thermal Biology, 56 (2016): 18-30. 

Logan Baker, Jordan Cameron, Cassidy Casteel, Kaylin Duritsch, Drew Edwards, Chance Humphrey, Ashley Murphy, Sierra Rolfes, Samantha Sicree, and Nicholas Vogt, all of Miami University Hamilton

Submitted By
Tory V. Pearman, Miami University Hamilton