A 22-year-old male is brought to the emergency department by campus police after being found wandering on a university campus at 2 AM, speaking incoherently, and appearing to respond to internal stimuli. On examination, he is agitated, disoriented to time and place, and reports seeing 'shadow people' in the corners of the room. His vital signs reveal tachycardia (heart rate 118 bpm), hypertension (158/96 mmHg), diaphoresis, and mydriasis. His temperature is 100.4 degrees Fahrenheit. He has horizontal nystagmus and displays intermittent muscle rigidity. His speech is tangential and pressured. His roommate, who accompanied him, reports the patient was at a party earlier in the evening and was acting normally until approximately 3 hours ago. The roommate states the patient has no psychiatric history and has never exhibited behavior like this before. A urine drug screen is pending. Which of the following is the most important initial clinical consideration?