This is a textbook case of mass hysteria. A whole lot of people in one place, all coming down with a mystery illness, with no apparent cause, and everyone has different symptoms. Instances like these have been reported multiple times in the past 20 years, as well as for thousands of years in the past. They all genuinely feel the symptoms. But the cause is clearly no physical thing in the environment.

> But the cause is clearly no physical thing in the environment.

And you're 100% sure on that?