In and around Mecca, periods of dangerous heat are occurring more often — and they last longer. A recent analysis finds that human-caused warming is a major factor making such conditions increasingly likely to affect the Hajj. This raises risks for millions of pilgrims and places growing strain on logistics and services.
Why heat is especially risky during the Hajj
The pilgrimage concentrates huge numbers of people in a small area over a few days. Limited air circulation, restricted access to drinking water, the physical exertion of rituals and often long distances to walk already increase strain at moderate temperatures. As ambient temperatures climb, critical physiological thresholds are reached more quickly. Older adults, young children and people with pre-existing conditions are particularly vulnerable.
Key findings of the analysis
Based on observed data and model comparisons that remove human emissions, researchers show that in recent decades the intensity, frequency and duration of dangerous periods in the region have increased. Time windows that were previously considered comparatively safe are slipping more often into categories with high health risk. Without the added greenhouse effect, recent extremes would have been rarer or less severe. That raises the probability that the Hajj will coincide with days of intense heat exposure.
Consequences for medical services and organization
facilities must absorb more heat-related emergencies: adequate fluid supply, medical care and rapid cooling options are central. Organizers need tighter coordination among authorities, health services and security forces — with additional water stations, more shaded areas, air-conditioned rest zones and fast transport routes for emergencies. Operational adjustments such as staggered timings, early-warning systems and clear information chains help ease peak loads.
Longer hazard periods and growing pilgrim numbers
Two trends reinforce each other: the risk of dangerous heat now extends over more months, while pilgrim numbers are expected to rise over the long term. Together, these factors increase the number of people potentially affected and heighten demands on and emergency responders.
Adaptation reduces risks — but climate mitigation remains decisive
In the short term, shade structures, mobile cooling stations, expanded drinking-water provision, medical preparedness and targeted communication can reduce risks. Shifting activities to cooler times of day and structural improvements to routes and squares also help where feasible. In the long term, however, the global emissions trajectory determines how often events occur. Without ambitious climate mitigation, more intense and longer-lasting heat episodes will threaten even well-prepared operations.
Political and ethical dimensions
Rising heat exposure raises questions about health protection, religious practice and international responsibility. Protective measures require substantial resources. Cooperation — for example in sharing best practices, medical assistance and climate- planning — can materially reduce risks for pilgrims.
What should be prioritized now
Short term: better cooling and drinking-water , health screenings, training for rescue teams, and clear, multilingual warnings and action guidance. Authorities should expand heat monitoring and early warning. Medium term: -climate measures such as greening, reflective surfaces and adapted building practices are sensible. Countries of origin and travel partners can offer targeted support to vulnerable groups and coordinate protection standards.