A record-breaking heatwave is sweeping across South Asia, pushing temperatures to dangerous highs and disrupting daily life for hundreds of millions of people in India, Pakistan and Bangladesh. Some areas have seen thermometers approach or exceed 45–50 degrees Celsius (113–122°F), well above seasonal averages for this time of year. In Pakistan's port city of Karachi, temperatures hit 44°C (111°F) — the highest recorded there since 2018 — with local emergency services reporting at least 10 heat-related deaths in a single day. In India, cities in Maharashtra such as Akola and Amravati recorded nearly 47°C in late April, while local media noted that more than 90 of the world's hottest cities were in India on a single day that month. Multiple fatalities, including two school teachers who died of heatstroke, have been reported across several Indian states.

Scientists and meteorological agencies say the intensity, duration and geographic spread of this heat event are unprecedented, even for a region accustomed to fierce pre-monsoon summers. High-pressure systems are trapping hot air near the surface in a "heat dome" effect, blocking clouds and allowing relentless solar heating. Weak pre-monsoon rains and lingering El Niño-like atmospheric patterns — El Niño being a periodic warming of the eastern Pacific Ocean that disrupts global weather — are further suppressing any cooling. The World Meteorological Organization has warned of high confidence that a new El Niño event could intensify from as early as May to July. Experts are increasingly linking the growing severity of such events to human-driven climate change, which amplifies extreme weather patterns even where it does not necessarily increase their frequency.

The crisis is exposing deep inequalities in who is most able to cope. Researchers at Harvard University's Mittal South Asia Institute estimate that roughly 380 million Indians — around three-quarters of the workforce — are engaged in heat-exposed labour, with informal workers and daily-wage earners falling largely outside the protection of existing Heat Action Plans. Physiological risks include cardiovascular strain, kidney injury, disrupted sleep and worsening of chronic conditions such as diabetes, with the elderly, pregnant women, young children and those with pre-existing illnesses facing the greatest danger. In Bangladesh, authorities recorded 24 heatwave days in April 2024 — the most in 75 years — underscoring a worsening multi-year trend across the subcontinent.

Governments are stepping up emergency responses, though experts warn that existing systems are not reaching the most vulnerable. India's Union Ministry of Housing and Urban Affairs has issued an advisory directing urban local bodies to ensure that homeless shelters are stocked with drinking water, oral rehydration salts, functional fans and cooling supplies such as wet towels, while calling for city-level rescue teams, activated helplines and trained staff who can identify heat-related illnesses. Pakistan's meteorological department has urged citizens to avoid direct sunlight during the day and remain hydrated, as cities in the Sindh province — a flat, arid region in the country's southeast — brace for temperatures as high as 46°C in the days ahead.

The heatwave has added urgency to broader conversations about long-term climate resilience. At the Breathe Pakistan International Climate Change Conference, held in Islamabad this week, policymakers, UN officials and civil society representatives warned that climate change had moved beyond being an environmental concern to become a fundamental development and economic challenge. Speakers stressed that vulnerable communities — including women, informal workers and the urban poor — must be placed at the centre of adaptation planning, and that climate finance must be restructured to reach those who need it most. As a UN official put it, South Asia's predicament "is not unique to Pakistan — it reflects a reality across the region", one that only coordinated, adequately funded action can begin to address.