Final answer:
The PN should immediately instruct the client experiencing high fever, muscle stiffness, and sweating while on antipsychotic medication to seek emergency medical attention, as these may be signs of neuroleptic malignant syndrome.
Step-by-step explanation:
The practical nurse (PN) should advise the client reporting muscle stiffness, a high temperature, and sweating while on antipsychotic medication to seek immediate medical attention. These symptoms may indicate a potentially serious side effect known as neuroleptic malignant syndrome (NMS), a life-threatening condition associated with the use of neuroleptic drugs. The PN should recognize the urgency of the situation and instruct the client or a caregiver to call emergency services or go to the nearest emergency room.
Further assessment and treatment should only be performed by medical professionals. The nurse should also document the call, the symptoms reported by the client, and the recommendation given, in the client's medical record for continuity of care and for the reference of other healthcare providers.