Editing Environmental and Public Health (section)

=== Thermoregulation and Cardiovascular Strain ===
Humans maintain a core body temperature of roughly 37°C. When exposed to extreme heat, the autonomic nervous system triggers two primary cooling mechanisms: vasodilation (widening of blood vessels near the skin to radiate heat) and sweating (evaporative cooling). 

Both mechanisms place immense strain on the cardiovascular system. To push blood to the skin's surface, the heart must beat faster and pump harder. For individuals with pre-existing cardiovascular conditions, the elderly, or those taking certain medications, this increased cardiac demand can lead to fatal heart attacks or strokes. Additionally, excessive sweating without adequate fluid replacement leads to severe dehydration, which can precipitate acute kidney injury and eventually renal failure.