Clinical presentation of thyroid storm is usually nonspecific. Diagnosis and treatment may be delayed if the emergency physician is not familiar with the disease. We report on a patient with a prior history of hyperthyroidism, suffering from abdominal pain, nausea and diarrhea for two days, followed by fever for one day. She received an initial diagnosis of infective gastroenteritis. Disturbed consciousness later developed and thyroid storm was eventually confirmed. The patient recovered after appropriate treatment. Differential diagnosis of hyperthyroidism patients presenting with diarrhea, fever, and disturbed consciousness should include thyroid storm, even with a history of travel to developing countries.