Heat Exhaustion on Hai Van Pass: How They Spot It Before You Do
The human body is remarkably bad at monitoring itself under heat stress.
This isn’t weakness. It’s physiology. When your core temperature rises, your brain gets busy managing the crisis—diverting blood to the skin for cooling, triggering sweat response, maintaining critical organ function. Self-awareness drops down the priority list. By the time you feel like you’re overheating, you’ve often been overheating for twenty minutes.
In a Vietnamese cycling context, those twenty minutes could be the difference between “let’s cool you down” and “let’s call an ambulance.”