Conflicts of interest:All authors have participated at events as volunteers and in contracted roles as operational and clinical care providers. Dr. Gutman is the president of Rockdoc Inc., an event operations company.Turris SA, Camporese M, Gutman SJ, Lund A. Mass-gathering medicine: risks and patient presentations at a 2-day electronic dance music event -year two. Prehosp Disaster Med. 2016;31(6):687-688.In June of 2015, Prehospital and Disaster Medicine published a paper on the impact of a higher level of care team on ambulance transfer rates (ATRs) during an urban, indoor music festival that took place over two consecutive days, for six hours each evening.1 This was a somewhat unique event as many music festivals are outdoor events and include "residential" camping on-site. The observational study presented the data from 2013 and documented patient presentation rates (PPR), case mix, and ATRs. One outcome of particular interest was the impact of a multi-disciplinary team capable of providing care similar to that available in the emergency department, with a specific focus on reduction of ATRs.We repeated the deployment in 2014, at the same music festival, and again embedded a data collection team in the deployment (HA, MC, ST, and SV). Details regarding the methodology are available in the original paper. The study received ethical approval from the University of British Columbia (Vancouver, British Columbia, Canada). In this letter, we briefly report the findings from 2014, the second year and final year of the study.In 2014, there were roughly 10,000 attendees on each of the two nights the event was held. One hundred individuals sought medical care in the field clinic during the event (N = 100; 49% first night and 51% second night). The average age was 19.49 years (range: 12-30 years). Forty-seven individuals (47%) treated were less than 19 years of age (the legal age for consuming alcohol). Sixty-three percent were female. Individuals arrived at the field clinic on foot (n = 59), by wheelchair (n = 37), and by stretcher (n = 4). The minority of patients arrived unaccompanied (n = 14), escorted by friends (n = 6), or with security services (n = 5). Most were escorted by members of the roving medical teams (n = 68): venue medical staff (n = 18) or contracted medical staff (n = 50). Seven arrivals were not documented.There were 53 non-acute presentations (eg, knee pain or headache), and 47 were classified as potentially urgent (n = 39; eg, moderate shortness of breath or moderate allergic reaction) or emergent (n = 8; eg, overdose or poisoning, seizures, or altered level of consciousness). Accordingly, alcohol use was documented as a contributing factor for 71/100 individuals. Recreational drug use was documented in 32/100 cases. Use of 3,4-methylenedioxy-N-methylamphetamine (MDMA), or a product sold as MDMA, was the most common form of substance use disclosed (n = 30; ie, "Ecstasy" or "Molly"). Other intoxicants reported included gamma-hydroxybutyric acid/GHB (n = 1) and cocaine (n = 4).A total of seven indi...