Karachi’s worsening urban heat is emerging as a serious public health challenge, with experts warning that rising temperatures, pollution and unchecked urban development could have severe consequences for residents, particularly vulnerable communities.
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Speaking ahead of World Environment Day, Prof. Zafar Fatmi, Head of Environmental Occupational Health and Climate Change at the Aga Khan University’s Department of Community Health Sciences, stressed that the city’s urban heat effect is intensifying due to both global climate change and local urbanisation patterns.
According to Prof. Fatmi, rapid expansion of concrete infrastructure, dense construction, traffic congestion, shrinking green spaces and widespread tree loss are causing Karachi to absorb and retain more heat. He cited a 2026 multi-city study that found Karachi had the highest urban-rural temperature difference among major Pakistani cities, averaging around 4.5 degrees Celsius.
Research conducted in the city has also revealed that people working outdoors often experience temperatures significantly higher than official weather readings. A 2024 study found delivery riders and rickshaw drivers were exposed to temperatures up to 5.5°C higher under direct sunlight than the city average.
The expert warned that signs of escalating urban heat are already visible, including warmer nights, increased dehydration, fatigue, headaches, dizziness and poor sleep. Elderly people, children, pregnant women and individuals with chronic illnesses are among the most vulnerable groups, alongside outdoor workers such as construction labourers, traffic police, vendors and delivery riders.
Prof. Fatmi also highlighted the combined impact of heat and air pollution, noting that exposure to both can significantly increase health risks. He added that rising temperatures may contribute to greater risks of mosquito-borne, water-borne and food-borne diseases, particularly in areas with poor sanitation and drainage systems.
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He called for a comprehensive heat-health action plan that includes shaded public spaces, drinking-water facilities, cooling centres, worker protections and improved public awareness. Long-term measures, he said, must focus on expanding green spaces, protecting trees, improving public transport and reducing emissions to make Karachi more climate resilient.