Mass gatherings create challenges for timely and efficient medical response. Compounded by exceptional noise from cheering crowds and ambient entertainment, compacted audiences form predictable barriers to patient sightings and access. Timely access also may be complicated by steep arena stairwells or poorly-defined locations along a longitudinal raceway, parade, or beachside festival. On-scene responders often encounter fixed barricades, inebriated crowds, obtrusive noise, and relative distances from on-site medical aid centers. Very often, potentially ill or injured persons are adamantly set against leaving their coveted position in the audience having purchased expensive tickets, traveled far and awaited many months, or even years, to be there. Once retrieved, patients need to be conveyed with protective measures and evaluated appropriately despite resource-limited settings and often pervasive heat, humidity and intoxication. Accordingly, patient identification, intra-site retrieval, evacuation, tracking, and communications need to be optimally planned and well-coordinated to mitigate these challenges. Recent experiences have provided evolving insights into best practices for mass gathering medical professionals. Many are addressed within this discussion including definitions for reportable patients, use of spotters and geospatial applications, coordinated tandem response with security personnel, dedicated record-keepers at medical care sites and electronic tracking devices for vulnerable populations and even entire audiences.

While all mass gatherings create significant challenges for delivering optimal medical care, music concerts and festivals engender additional concerns ranging from a higher likelihood of toxicological, topographical, meteorological and sociological risks to additional threats from violence, injury and even food-borne illness. Locating patients can pose challenges among packed audiences in the dark and din of massive crowds and blaring entertainment. Multi-day music-related festivals, particularly those including on-site overnight camping, can pose additional and often escalating risks day-by-day.

Planning risk assessments can be multi-variate and dynamic in nature. Medical planners may first tailor plans based on historical experiences, evolving new intelligence or even developing external threats, but available tools for calculating risk for each type of threat can better quantify concerns and justify additional funding and resources for the best possible medical care and health security. Beyond basic considerations such as estimated crowd size and density, location of the venue, and event-specific medical considerations, mass gathering medicine clinicians and planners need to navigate some variable considerations including climate, weather, type of event, specific site structures, the organizers’ expectations and even typically unanticipated types of events such as terrorism, stampedes, contaminated food and some previously-unrecognized lethal drugs being passed around to attendees.