This report describes the clinical characteristics, treatment, and pathologic mechanisms of neonatal ultrahyperpyrexia syndrome induced by improper care. Clinical data on 14 cases of neonatal ultrahyperpyrexia syndrome induced by improper care were retrospectively analyzed. All 14 neonates had become comatose with ultrahyperpyrexia or hyperpyrexia; 8 of these patients twitched, 12 had high muscular tension, 2 exhibited low muscle tone, and 9 had respiratory dysfunction. Computed tomography revealed a patched, low dense shadow in the frontal and parietal lobes of the cerebral cortex in 9 patients; local cerebral hemorrhage occurred in 3 cases, and subarachnoid hemorrhage was reported in 2. After systematic treatment was provided, 13 neonates survived, but 1 died. Dysfunction of the neural, respiratory, and circulatory systems was the main pathologic mechanism noted in these cases of neonatal ultrahyperpyrexia syndrome induced by improper care. Early treatment, acute hypothermia, and supplemental fluids are the keys to successful therapy.