An 18-year-old man suffered heat stroke after continuous working for 26 hours on his first day in an aluminium utensil plant in August 1998. His job was to put a pressed aluminium utensil on the conveyer before the process of spray painting. The ranges of temperature and relative humidity measured at the local weather-station during the patient' s working period were 23.6-30.2 degrees C, 49-87 % respectively. On arrival the patient was comatose and suffered generalized seizure three times. His rectal temperature was 41.2 degrees C . blood pressure was 90/60 mmHg, pulse was 148 beats/minute and respiratory rate was 28 times/minute. The serum level of AST was 421 IU/L. ALT was 205 IU/L, LDH was 1,160 IU/L. myoglobin was higher than 500 ng/mL. OK was higher than 2,000 IU/L. He recovered consciousness 7th day of admission and discharged after 2 months but cerebellar dysarthria was remained. The patient felt himself several prodromal symptoms of heat stroke and he showed awkward behavior considered to be drowsiness, but the patient and his co-workers neglected them. This case report shows that heat stroke can be occurred in a condition that ambient temperature, humidity, and working load are not extreme. A thorough health education and management concerned with guidelines on salt and water intake, detection of early symptoms of heat-related illness, prompt body cooling and rapid transportation to a hospital is necessary.