As we walk inside, I can taste metal in my gums. It feels like crossing a doorway from an air conditioned room into a desert but instead of entering a wall of heat, I’m met with a vapor cloud of chemicals—hot, sticky, metal-tasting chemicals. Ammonia I recognize, then something else. I can’t identify it. Before the thought has a chance to linger, all of my senses are overwhelmed. Burning nostrils, watering eyes, raw throat. I look back at our crew and see everyone waging their own battles—blinking eyes, covering mouths. Everyone fights the urge to turn around. The cool, misty air of the Himalayan foothills, some three hundred miles upstream, is already a distant dream.

Quickly I feel queasy, unstable.