Final answer:
The nurse should report hyperthermia to the provider as it is a manifestation of neuroleptic malignant syndrome (NMS), a serious side effect of antipsychotic medications like haloperidol.
Step-by-step explanation:
The nurse should report hyperthermia to the provider as a manifestation of neuroleptic malignant syndrome (NMS) when assessing a client with schizophrenia taking haloperidol. NMS is a serious side effect associated with antipsychotic medications, such as haloperidol, and can be life-threatening.
Symptoms of NMS include severe muscle rigidity, fever (hyperthermia), altered mental status, and autonomic dysfunction. Hyperthermia stands out as a key indicator of NMS compared to the other options provided: increased appetite, bradycardia, and excessive salivation.