Oak (Quercus species), particularly the bark, has been used in various traditional medicine systems, including European folk medicine and Native American herbalism. Historical records suggest that oak bark decoctions and infusions were sometimes employed to reduce fever, although this use was much less common than its employment for diarrhea, wounds, and skin ailments. The underlying rationale for its use in fever management was typically its astringent and anti-inflammatory properties attributed to high tannin content. However, there is little direct ethnobotanical or pharmacological literature detailing oak's specific efficacy as an antipyretic (fever-reducing) agent.

Modern scientific studies on oak bark primarily focus on its antimicrobial, antioxidant, and anti-inflammatory properties, but there is no robust clinical or preclinical evidence that directly supports its use for treating fever. No major pharmacopoeias or herbal monographs (such as those from the European Medicines Agency or Commission E) list oak as an antipyretic. Thus, while oak has a minor traditional association with fever treatment, this use is poorly documented and not supported by scientific research. Its primary and better-supported traditional uses remain for gastrointestinal and topical applications.