A nurse in an emergency department is caring for a client who is confused and has a temperature of 40.1° C (104.2° F). Which of the following actions should the nurse take?

Nursing care for a client with severe hyperthermia and altered mental status focuses on rapid temperature reduction and prevention of neurologic injury and organ dysfunction. A temperature of 40.1°C (104.2°F) indicates a potentially life-threatening hyperthermic state that requires immediate active cooling measures. The priority is to reduce core body temperature safely while supporting circulation and preventing complications such as seizures, dehydration, and heat stroke-related organ damage. Intravenous cooling and external cooling strategies are commonly used together in emergency management. Rationale: A. Administering cooled 0.9% sodium chloride solution is appropriate because it helps lower core body temperature while also supporting intravascular volume. In severe hyperthermia, patients often experience dehydration and electrolyte imbalance due to excessive heat and fluid loss. Cooled IV fluids provide internal cooling and stabilize circulation, making them a key intervention in emergency temperature management. B. Checking the client's temporal temperature every 15 minutes is not the priority intervention because continuous temperature monitoring alone does not actively reduce hyperthermia. While frequent monitoring is important to evaluate response to treatment, the immediate need is active cooling rather than observation. Delaying treatment while frequently reassessing temperature could allow progression of organ damage. C. Giving an acetaminophen suppository is not appropriate because antipyretics are ineffective in true hyperthermia caused by environmental or severe physiologic heat overload. Acetaminophen acts on the hypothalamic set point, which is not the primary issue in this situation. Therefore, it will not significantly reduce body temperature in severe heat-related illness. D. Starting an infusion of pancuronium is inappropriate because neuromuscular blocking agents do not treat hyperthermia and do not reduce core temperature. Pancuronium is used to induce paralysis in controlled settings such as mechanical ventilation but does not address the underlying cause of elevated temperature. Additionally, it would mask motor responses, potentially delaying recognition of worsening clinical status.