Serotonin syndrome is a toxic state caused mainly by excess serotonin within the central nervous system. It results in a variety of mental, autonomic and neuromuscular changes, which can range in severity from mild to life-threatening.
Often encountered at music festivals, (though it may be a while until we see any) we recently had a patient present with moderate symptoms on road.
New South Wales Ministry of Health have a set of guidelines for harm reduction at music festivals, including illicit substance-induced hyperthermia. The guideline can be found here:
https://www.health.nsw.gov.au/aod/Factsheets/illicit-substance-induced-hyperthermia.pdf
For further reading: