I'm a clinic MP (in my country, similar to a nurse practitioner) and I work in an overnight emergent access clinic. Alot if what we see is walk-in clinic level, but occasionally we get something serious.
A local high school had some sort of overnight event. In the course of 2 hours, ambulances were contacted for 6 students for similar symptoms. Severe headache, emotional duress, agnor animi, and nausea. Ambulances ended up being deferred, and school staff + community first responders transported all 6 students to our clinic. A 7th patient, a teacher, came soon thereafter.
Ensuring to cover all of our bases, we made sure to work up each patient as an individual case. Only one patient set off our triage alarm bells (photophobia, stiff neck, crisis level hypertension). That patient ended up having a subarachnoid hemorrhage confirmed via CT and was brought via critical care ambulance to a neurosurgical hospital.
Everyone else ended up having symptoms resolve after an hour of being seperated, placed into observation, given low dose anxiety medication, and reassured only one person had an issue and that was non-contagious.
Source: Original link