If the temperature reaches the extremely high level of hyperpyrexia, aggressive cooling is required.
From the en.wikipedia.org
Less common symptoms such as tachycardia, convulsions, vomiting, hypertension, hyperpyrexia and ataxia have all been noted.
From the en.wikipedia.org
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Extremely high fever (especially in children)
Fever (also known as pyrexia or controlled hyperthermia) is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.