An adolescent patient with acute abdominal pain and vomiting presented in the emergency room. Bathing in hot water relieved his symptoms. Physical examination, basic laboratory testing and imaging showed no abnormalities. The patient was diagnosed with cannabinoid hyperemesis syndrome, which is characterized by chronic cannabis use, recurrent episodes of intractable vomiting and compulsively hot showering or bathing to relieve the symptoms. Unfamiliarity with the syndrome can easily lead to unnecessary diagnostic testing and inappropriate treatment. The consulting psychiatrist could play a role in the diagnostic process and treatment. Furthermore, early recognition of this syndrome in the emergency room may lead to a proper addiction treatment program.