Geneva: The World Health Organization has issued new public-health guidance aimed at reducing heat-related illness during mass gatherings, as extreme temperatures increasingly create risks for people attending outdoor events and large public activities.

The guidance is designed to help governments, event organisers and health authorities prepare for periods of extreme heat and protect people who may be particularly vulnerable to high temperatures.

Heat can become a serious health risk

Prolonged exposure to high temperatures can place significant stress on the human body.

Heat exhaustion can develop when the body loses excessive amounts of water and salts. In more severe cases, extreme heat can cause heatstroke, a potentially life-threatening medical emergency.

Large gatherings can increase these risks because thousands of people may remain outdoors for extended periods, sometimes with limited access to shade, drinking water or medical assistance.

Event planning becomes important

WHO’s guidance emphasises the importance of preparing for heat before an event begins.

Organisers can monitor weather forecasts, identify potential heat risks and establish procedures for responding to dangerous temperatures.

Measures such as shaded areas, drinking-water stations, ventilation and accessible medical facilities can help reduce exposure.

Vulnerable people require additional protection

Some people are more susceptible to heat-related illness than others.

Older adults, young children, pregnant women and people with certain underlying health conditions may be particularly vulnerable.

People who work outdoors or participate in strenuous physical activity can also face increased risk during extreme heat.

Warning signs should be recognised

Early recognition of heat-related illness can help prevent more serious complications.

Symptoms of heat exhaustion may include heavy sweating, weakness, dizziness, headache, nausea and faintness.

Heatstroke is more serious and can involve confusion, loss of consciousness, seizures and very high body temperature. It requires urgent medical attention.

Hydration and cooling measures

Maintaining adequate fluid intake is an important part of heat protection.

Event organisers can make drinking water easily accessible and encourage participants to take regular breaks from direct sunlight.

Cooling areas can also provide relief during periods of extreme heat.

Emergency plans are essential

Large events need clear emergency procedures for situations involving multiple heat-related illnesses.

Medical teams should be prepared for an increase in heat emergencies, while organisers should have communication systems capable of quickly informing participants about dangerous weather conditions.

Climate change increases concern

The new guidance comes as countries around the world experience more frequent and intense periods of extreme heat.

Climate change is increasing the likelihood of heatwaves in many regions, creating additional challenges for public-health systems.

Mass gatherings can be particularly challenging because large numbers of people are concentrated in one location at the same time.

Protecting public health

WHO’s guidance highlights the importance of treating extreme heat as a major event-planning issue rather than simply a weather inconvenience.

Early preparation, access to water, shaded and cool areas, medical support and effective public communication can help reduce health risks.

As extreme heat becomes an increasingly important public-health concern, integrating heat-safety measures into mass-gathering planning can help protect participants, workers and local communities.