A 27-year-old woman was hospitalized for the treatment of new-onset seizures, fever, tachycardia, hypertensive crisis, and anasarca. Two weeks prior, severe hyperthyroidism with thyroid storm was diagnosed (Burch-Wartofsky score, 60 points) and she was treated with potassium iodide–iodine (Lugol solution), hydrocortisone, methimazole, and propanolol.