<prompt> A patient was on treatment with trifluoperazine for some time. He presents with a complaint of hyperthermia, lethargy and sweating. Needed investigations are -CT Scan brain hemogramHemogram, Electrolyte level and creatinineECG, Chest X-ray and hemogramHemogram, CPK and renal function test  <response>: Hyperthermia, lethargy and sweating in a patient on antipsychotic trifluoperazine suggest the diagnosis of the neuroleptic malignant syndrome.The rigidity and hyperthermia found in neuroleptic malignant syndrome contribute to muscle damage and necrosis. This can cause:-Elevated serum creatine kinase CK Serum CK level should be assessed. Assessment of elevated CK level is the most commonly used laboratory investigation for the neuroleptic malignant syndrome.Elevated blood myoglobin myoglobinemia and myoglobinuria which can cause renal failure renal function test should be done.Leucocytosis thrombocytosis Hemogram should be evaluated. 