These are all possible signs of neuroleptic malignant syndrome (NMS), a rare but serious adverse effect of risperidone and other antipsychotic medications.

NMS is a life-threatening condition that requires immediate medical attention. It is characterized by fever, muscle rigidity, altered mental status, autonomic instability and elevated creatine kinase levels.

Choice B is wrong because polyuria is not a common side effect of risperidone. Polyuria can be caused by other conditions such as diabetes mellitus, diabetes insipidus or diuretic use.

Normal ranges for vital signs and laboratory values are as follows:

• Temperature: 36.5°C to 37.5°C (97.7°F to 99.5°F)

• Heart rate: 60 to 100 beats per minute

• Blood pressure: 120/80 mm Hg or lower

• Respiratory rate: 12 to 20 breaths per minute

• Oxygen saturation: 95% or higher

• Creatine kinase: 22 to 198 U/L for males and 10 to 171 U/L for females