Heal-All (Prunella vulgaris) has a long history of use in traditional herbal medicine across Europe, Asia, and North America, where it was often used as a general remedy for various ailments, including fever and chills. Folk practitioners have used Heal-All as a tea or infusion to support the body's resistance to infections and to alleviate symptoms such as chills, which often accompany feverish illnesses.

However, direct evidence specifically linking Heal-All to the treatment or reduction of chills is sparse. Most references in ethnobotanical literature are anecdotal or part of broader recommendations for fevers and "colds," rather than chills alone. The plant does contain compounds like rosmarinic acid and ursolic acid, which have demonstrated anti-inflammatory and mild antimicrobial properties in laboratory studies, but there is no clear clinical evidence demonstrating efficacy for chills specifically.

In summary, the use of Heal-All for chills is based primarily on traditional usage rather than solid scientific validation. While there is some plausible rationale for its inclusion in historical remedies for feverish conditions (which may include chills), there is a lack of robust evidence to support its specific use for this symptom.