Heat stroke occurs when body thermal regulation is upset and unable to dissipate adequate amounts of heat with rise in body temperature. Thus heat stroke may result in rhabdomyolysis and multiorgan failure. We observed two childhood cases of heat stroke with rhabdomyolysis and multiorgan failure. One case was caused by accidentally being left in a car trunk for 3 hours on a sunny afternoon in late spring and the other case occurred climbing a mountain on a hot summer day during a school trip for improving individual self-control. The first case, a boy almost 5 years old, displayed thetypical clinical features of heat stroke including hyperpyrexia, CNS disturbance, hot dry skin, acute liver failure, rhabdomyolysis, oligo- anuric acute renal failure, and disseminated intravascular coagulopathy. He was treated with general supportive care and daily hemodialysis. Despite the aggressive management, he died of shock on the sixteenth day of admission day. The second case, a 14-year-old middle school boy, displayed similiar features of the first case but showed milder symptoms. He was also treated with general supportive care and daily hemodialysis for 10 days. He recovered completely and was discharged in good condition. The public including medical and paramedical personnels should be warned of the dangers of childhood heat stroke, which is potentially lethal, but preventable.