Phellodendron bark, known as "Huang Bai" in Traditional Chinese Medicine (TCM), has a longstanding history of use for treating fever and "damp-heat" conditions. Texts such as the Shennong Bencao Jing (Divine Farmer's Materia Medica, 3rd century AD) mention its use in clearing heat, reducing dampness, and alleviating symptoms associated with febrile diseases. Traditionally, it is prescribed for high fevers, night sweats, and conditions believed to be caused by internal heat or toxins.

From a scientific perspective, research on Phellodendron bark has primarily focused on its alkaloid content, particularly berberine, which exhibits anti-inflammatory, antimicrobial, and antipyretic (fever-reducing) properties in cell culture and animal studies. Some studies have demonstrated berberine's ability to reduce fever in animal models by modulating inflammatory cytokines and inhibiting prostaglandin synthesis. However, robust clinical trials in humans are lacking, and most evidence is preclinical or extrapolated from the known pharmacology of berberine.

In summary, while there is some mechanistic basis for antipyretic effects, the use of Phellodendron bark for fever is primarily supported by traditional use and limited preclinical evidence. High-quality human clinical trials are needed to validate its efficacy and safety for this indication.