WHO Warns Nigerians and Event Organisers About Heat Risks at Large Gatherings

People attending large sporting events, religious gatherings, festivals and other crowded events could face preventable health risks from extreme heat, prompting the World Health Organisation (WHO) to issue new guidance for governments and event organisers.

The guidance calls for practical measures such as accessible drinking water, toilets, cooling facilities, adjusted schedules, crowd-flow management and medical services at venues. WHO says these measures can help protect not only attendees but also workers, volunteers and event staff.

The WHO released its new guidance on Wednesday, September 30, 2026, following a review of evidence from mass gatherings around the world.

The evidence review examined studies published between 1980 and 2025 and documented nearly 500,000 medical encounters at mass gatherings, including more than 22,000 heat-related illnesses.

WHO said the evidence showed that more than 90 per cent of patients can be treated at event venues when on-site medical systems are properly organised. This can reduce pressure on local hospitals and ambulance services.

The organisation's guidance covers major sporting, religious and cultural gatherings and is intended to be used throughout the event cycle, from preparation through the event itself and recovery afterwards.

Mass gatherings can create conditions that make heat exposure more dangerous.

WHO identified prolonged outdoor exposure, dense crowds, limited access to safe drinking water, travel-related stress and unfamiliarity with local climatic conditions as factors that can increase risk.

People may also spend several hours walking, standing or participating in activities while exposed to high temperatures. At the same time, large events can increase demand for emergency medical services.

WHO's guidance therefore treats heat management as more than an individual's responsibility. It calls for organisers and authorities to build heat protection into the design and operation of events.

The new guidance recommends a range of measures, including:

- Accessible safe drinking water.

- Adequate toilets and sanitation.

- Cooling infrastructure and shaded or cooler areas.

- Adjustments to event schedules when heat risk is high.

- Effective crowd-flow management.

- Protection for workers and volunteers.

- Public communication about heat risks.

- Real-time health surveillance.

- Properly prepared medical teams at event venues.

WHO says venue design, transportation, security, communications, water and sanitation can all affect whether people can reach cooling facilities or receive medical attention quickly.

The WHO said heat-related deaths have increased by an estimated 63 per cent since the 1990s, with an average of 546,000 heat-related deaths annually between 2012 and 2021.

That figure comes from the 2025 Lancet Countdown assessment, which estimated average annual heat-related mortality at about 546,000 during 2012–2021, compared with about 335,000 during 1990–1999.

The WHO also cited the Intergovernmental Panel on Climate Change (IPCC), which says hot extremes, including heatwaves, have become more frequent and intense across most land regions since the 1950s, largely because of climate change.

For people attending major events, the guidance means that protection from extreme heat should not depend entirely on whether an individual remembers to drink water or find shade.

Organisers have a role in making those protections available.

This is particularly relevant to events where people may spend long periods outdoors or in crowded conditions, including sporting competitions, religious gatherings, festivals and cultural celebrations.

The WHO's evidence also suggests that having medical personnel and appropriate facilities at the venue can make a significant difference. When those systems are well organised, more than nine out of 10 patients in the reviewed evidence could be treated without requiring transfer to a hospital.

That can matter for both the individual affected and the wider health system, because unnecessary transfers can add pressure to ambulances, emergency departments and other local medical services.

WHO Executive Director for Health Emergencies, Dr Chikwe Ihekweazu, said extreme heat should be treated not only as an environmental hazard but also as an operational and governance issue.

The organisation's new framework therefore extends beyond first aid. It considers how an event is planned, how people move around the venue, how water and sanitation are provided, how warnings are communicated and how medical teams respond when heat risks increase.

WHO says the guidance is designed to complement national heat-health action plans, occupational health and safety requirements, emergency preparedness arrangements and clinical guidance.

WHO is urging governments, event organisers and other partners to incorporate heat-risk management into the planning and operation of mass gatherings.

The organisation has also released a separate risk-assessment tool designed to help organisers conduct structured assessments before and during events.

The recommendations are intended to be applied across the full lifecycle of an event, including preparation, impact mitigation and recovery.

Extreme heat can turn a crowded public event into a health risk, but WHO's evidence indicates that many heat-related illnesses can be prevented or treated at the venue when organisers prepare properly.

For attendees, workers and volunteers, the practical message is straightforward: access to water, cooling, sensible scheduling, clear communication and timely medical care can all make large gatherings safer.