afebrile

adj. feverless, not feverish

Core temperature is the operating temperature of an organism, specifically in deep structures of the body such as the liver, in comparison to temperatures of peripheral tissues. Temperature control (thermoregulation) is part of a homeostatic mechanism designed to keep the organism at optimum operating temperature, as it affects the rate of chemical reactions. In humans this optimum temperature is (see Normal human body temperature). The condition of being at optimum temperature is called afebrile or apyrexic.
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Afebrile /afe·brile/ without fever. a·feb·rile adj. Apyretic. afebrile without fever. afebrile adjective Feverless [more]Afebrile - Community and Resources

Adjective
1. having no fever
(antonym) febrile, feverish
(pertainym) fever, febrility, febricity, pyrexia, feverishness

adjective
with no fever