Thinking · Duty of Care

WHO has made heat at mass gatherings an operational risk: India runs the largest gatherings on earth.

Abhijith Magal · 1 October 2026 · 8 min read

Heat safety at mass gatherings in India has, as of 30 September, an international reference document. WHO released Prevention and Management of Heat-Related Illness at Mass Gatherings, a suite built on systematic reviews of studies published between 1980 and 2025, alongside an implementation guide, a heat-risk assessment tool and evidence-based communication templates. The reviews document nearly half a million medical encounters at mass gatherings, more than 22,000 of them heat-related illness.

The sentence that moves this from public health to governance is WHO's own framing: extreme heat is an increasing threat to health, safety and operational continuity at mass gatherings. Operational continuity is boardroom language, deliberately. An event that medically collapses mid-afternoon is a failed event, whatever its attendance figures, and WHO's evidence says the collapse is largely preventable: most heat-related illness at gatherings can be prevented or treated at the venue when timely risk assessment, preparedness and response are in place.

Why gatherings concentrate heat risk

WHO's mechanism list reads like a description of an Indian mela. Prolonged time outdoors in direct sun. Dense crowds that trap heat and block airflow. Limited access to safe drinking water. Travel stress on the way in. Attendees unfamiliar with local conditions, pilgrims from cooler regions arriving into a plains summer. Add what the new WHO mortality estimates establish about who attends: in a population where three in four deaths run through chronic conditions, a crowd of a million contains hundreds of thousands of people whose heart, kidneys or lungs are the actual point of failure heat will find. WHO's guidance states plainly that heat worsens chronic disease.

The scale words matter here. The events WHO studied, Hajj included, are the global evidence base, and India's calendar exceeds all of it: Kumbh congregations measured in crores, annual pilgrimages in the tens of lakhs, election rallies and sports events filling summer afternoons. The country that runs the biggest gatherings on earth, in a warming that WHO cites as having raised heat deaths 63 per cent since the 1990s to an average of 546,000 a year between 2012 and 2021, is the natural first adopter of this guidance, and so far nothing obliges any Indian organiser to read it.

The duty-of-care reading

For Indian organisers, the suite changes the legal and reputational arithmetic the way international reference documents always do: by existing. A state health department, a municipal authority permitting a ground, an event company, a sports league or a temple trust that plans a hot-season gathering without a heat risk assessment is now choosing to ignore a published WHO standard with a free tool attached. That is the same structural shift I traced for employers in the workplace heat duty of care, applied to the event footprint, and it compounds with the operational record of public systems in the heat season and healthcare operations.

The syntropy here is that nothing needs inventing. India's large religious gatherings already run formidable temporary health systems; the Kumbh builds field hospitals. What the WHO suite adds is the planning-stage discipline: the risk assessment before permission, the written protocol with named owners, the water-and-shade build-out specified in advance, the on-site treatment standard. An organiser, or a sponsor with its brand on the event, can adopt the suite this winter and walk into next summer with the assessment done. For companies, sponsorship plus Section 135 money makes event heat-safety a fundable programme with a WHO anchor; the booking rules are in the CSR piece.

One limit. The suite is weeks old and carries no headline figures beyond its evidence review; the 500,000 encounters and 22,000 heat illnesses describe the studied literature, not an annual global toll, and event-level risk is local. The right use is the tool, run against a specific venue and date, not the citation alone.

Common questions

What did WHO release on heat and mass gatherings?

A resource suite, Prevention and Management of Heat-Related Illness at Mass Gatherings, published 30 September 2026: systematic reviews covering 1980 to 2025, an implementation guide, a heat-risk assessment tool and communication message templates, for sporting, religious and cultural events.

How big is the heat problem at mass gatherings?

WHO's evidence review documents nearly 500,000 medical encounters at mass gatherings, including more than 22,000 heat-related illnesses, and frames extreme heat as a threat to health, safety and operational continuity. WHO also cites estimates that heat deaths have risen 63 per cent since the 1990s, averaging 546,000 a year between 2012 and 2021.

What does the guidance recommend?

Risk assessment at the planning stage, accessible safe drinking water and toilets, cooling infrastructure, schedule adjustments away from peak heat, crowd-flow management, evidence-based public communication, and on-site medical capacity, since most heat illness at events can be prevented or treated at the venue.

Why does this matter for Indian event organisers?

India's melas, pilgrimages, rallies and tournaments are the largest gatherings anywhere, increasingly held in hot months. A published WHO standard with a free risk-assessment tool shifts the organiser's duty of care: running a hot-season event without a heat assessment is now a documented choice.

Abhijith Magal

Founder, Syntropy Earth. Nine years across two global pharmaceutical multinationals in patient access and commercial roles, with health-equity work alongside the WHO-Foundation and UNICEF. He works on climate-access: where climate disruption breaks the link between patients and care.

This page reads published guidance. It is not clinical or event-safety advice; heat illness management follows national guidelines and the advice of qualified professionals.

Last updated: 3 October 2026