The 20-year-old healthy soccer player is brought to the emergency department after collapsing at the end of a summer soccer game. The patient is lethargic and confused about the event. Upon assessment, the nurse notes flushed, dry skin that is warm to the touch. The oral mucosa is dry, as well. Vitals are as follows: temperature 40.7°C, heart rate 122 bpm, respiratory rate 20, and blood pressure 116/64 mmHg. A rectal thermistor is inserted and aggressive cooling measures are instituted. After 30 minutes in the ice bath, the patient’s rectal temperature is 39.1°C and the ice is partially melted. Which action by the nurse is most important?