A 42-year-old man from rural Maharashtra presents to the emergency department with severe burns over 60% of his body sustained 6 hours ago. On examination, he is tachycardic (HR 128/min), tachypneic (RR 32/min), and febrile (38.9°C). Blood glucose is 280 mg/dL despite no prior diabetes. His serum electrolytes show Na⁺ 148 mEq/L, K⁺ 3.2 mEq/L. Arterial blood gas reveals metabolic acidosis with pH 7.28 and HCO₃⁻ 14 mEq/L. The attending physician notes that the patient's metabolic rate has increased dramatically, with oxygen consumption far exceeding what would be expected from the degree of tissue injury alone. Which of the following best explains the uncoupling of oxidative phosphorylation occurring in this patient's mitochondria?