Brain Cooling in Fever A Hypothesis on Cognitive, Thyroid, and Thermoregulatory Mechanisms

This work presents the Brain Cooling in Fever hypothesis, which proposes that cognitive shutdown, thyroid hormone downregulation, and hierarchical thermoregulatory mechanisms function as purposeful strategies to protect the brain, a thermosensitive organ, from thermal overload during fever and infection. The hypothesis integrates physiological, clinical, and anatomical perspectives, reframing sickness behavior and non-thyroidal illness syndrome (NTIS) as active brain-protective processes rather than passive consequences of illness. Key sections discuss the thermoregulatory paradox in central nervous system infections, parallels with other thermosensitive organs, and the consequences of thermoregulatory failure in extreme states such as thyroid storm, myxedema coma, and septic hypothermia. The paper outlines implications for neurology, endocrinology, infectious disease, and critical care, and calls for interdisciplinary research using advanced brain thermometry and neuroimaging. Author:Dr. Ghassan Ahmed Mubasher MohamedsalihNeuro-Ophthalmologist, Hamad Medical Corporation, QatarORCID: https://orcid.org/0009-0000-7926-3150Email: [email protected]