A 58-year-old man presents to the emergency department after…
A 58-year-old man presents to the emergency department after spending several hours gardening and mowing the lawn in hot weather. He reports experiencing muscle cramps, dizziness, and excessive sweating before arrival. He has no significant past medical history and is generally in good health. On examination, his skin is warm and flushed, his heart rate is elevated, and he appears mildly confused. Laboratory tests reveal: serum osmolality: Elevated and serum sodium: Borderline high. What is the likely explanation for this finding?