Gastroenteritis, a common childhood illness, is characterized by symptoms such as diarrhea, nausea, vomiting, fever, and abdominal pain. One common nursing problem experienced by children with gastroenteritis is hyperthermia due to the inflammatory response caused by infection. The release of pyrogenic substances affects the hypothalamus, causing an increase in body temperature, which, if left untreated, can lead to serious complications including seizures and potential brain damage. The method used in this case study is a nursing process approach: assessment, diagnosis, planning, implementation, and evaluation.
The assessment results showed a patient with general weakness, a red face and skin, droopy eyes, a hot skin temperature of 39.4°C, and sweating on the forehead and back. Nursing care was provided to An.K in the Dahlia Room, Darmayu General Hospital, Ponorogo, for three days, from May 21–23, 2025. Interventions focused on managing hyperthermia with external cooling using warm compresses using the water tepid sponge method, monitoring body temperature, and collaborating on drug therapy. After three days of nursing intervention, An.K's hyperthermia problem could be resolved well with a body temperature examination result of 37°C.

Keywords: Pediatric Nursing Care, Gastroenteritis, Hyperthermia.