GENEVA / RankWire.AI / – To mitigate heat-related health issues during large-scale events worldwide, the World Health Organization (WHO) has introduced new guidance. This advice pertains to major sporting, religious, and cultural gatherings, focusing on risks faced by spectators, attendees, volunteers, and workers exposed to extended periods of high temperatures. An extensive review of evidence, covering studies published from 1980 through 2025, identified nearly 500,000 medical encounters at mass gatherings, with over 22,000 cases linked to heat-related illnesses.
The findings indicate that well-organized on-site medical services can address most health issues without the need for hospital transfers. When event organizers ensure that medical systems at venues are adequately prepared, over 90% of patients can receive treatment directly at the site. This approach alleviates burden on local hospitals and ambulance services. The guidance forms part of a comprehensive toolkit aimed at governments, event organizers, and health authorities, combining research insights with practical methods for assessing and managing heat risks both before and during major gatherings.
According to the guidance, heat-related fatalities have risen by approximately 63% since the 1990s. On average, 546,000 deaths each year between 2012 and 2021 were attributed to heat. Crowds in densely packed settings can increase exposure, especially when individuals remain outdoors in high temperatures for prolonged durations. Limited access to water, restricted mobility, and travel-related stress further heighten these risks. The high demand placed on health services can also hinder medical responses during such large-scale events.
Integrating heat preparedness into event operations
The new guidance emphasizes the importance of providing accessible drinking water, sufficient sanitation facilities, and cooling infrastructure at venues. It recommends schedule modifications, improved crowd-flow management, and protective measures for event staff. Organizers are encouraged to utilize public communication strategies, real-time health monitoring, and well-prepared medical services in their planning efforts. WHO underscores that heat protection should be an overarching aspect of the entire event rather than relying solely on individual actions. Aspects like venue design, transportation, security, and sanitation play critical roles in ensuring access to cooling and medical aid.
The comprehensive package includes systematic reviews, a manual for implementation, and a specialized heat-risk assessment tool. Additionally, it offers resources for crafting evidence-based public health messages during periods of elevated heat. This assessment instrument supports structured, repeatable reviews both before and during events. The overall framework addresses all phases—from preparation and impact mitigation to recovery—and can be integrated with existing emergency response plans, occupational safety protocols, and national heat-health strategies.
Supporting evidence for proactive heat precautions
The Intergovernmental Panel on Climate Change has reported that the frequency and severity of hot extremes have increased across most land areas since the 1950s. Elevated temperatures can intensify health risks during outdoor or crowded events. Vulnerable groups such as older adults, individuals with chronic conditions, and those engaged in physical activities face heightened danger. Workers and volunteers spending extended hours outside—providing security, transportation, medical, or logistical support—are also at increased risk.
The guidance advocates for incorporating heat management strategies into broader public health and emergency preparedness plans for mass gatherings. It urges authorities and organizers to continuously evaluate environmental and health conditions throughout the event lifecycle and to align health protection measures with operational planning. These recommendations apply to diverse event types and sizes, including international sports competitions, festivals, and religious gatherings. The focus remains on prevention, early intervention, and onsite care, while reinforcing existing national systems dedicated to heat-health management, emergency response, and clinical care.