The event itself is surprisingly low-key. The mood is one of stoic grimness. No one is screaming in pain. No one will be scarred by the heat. That’s not how capsaicin works. It only feels hot. The human tongue has pain receptors that respond to a certain intensity of temperature or acid. These nerve fibers send a signal to the brain, which it forwards to your conscious self in the form of a burning sensation. Capsaicin lowers the threshold at which this happens. It registers “hot” at room temperature. “It trips the alarm,” says Bruce Bryant, a senior researcher at the Monell Chemical Senses Center in Philadelphia. “It says, ‘Get this out of your mouth right now!’” The chili pepper tricks you into setting it free.

The whole affair is beginning to seem like an anticlimax when I look up from my notes to see Pu Zozam headed my way. I have seen people stagger in movies, but never for real directly in my sightline. Zozam’s legs buckle as he tries to keep walking. He goes down onto one knee and collapses sideways onto the floor. He rolls onto his back, arms splayed and palms up. He’s making sounds that are hard to transcribe. Mostly vowels.

A woman had an orgasm every time she brushed her teeth.