Karachi's Heat Crisis: What Grid Failure and Undercounted Deaths Reveal

In June 2024, morgue staff working with the Edhi Foundation in Karachi described receiving more than twice the usual number of bodies on some days. The official death toll for that heatwave was 427. The gap between those two facts is the story of heat mortality in Pakistan.

The scale of the problem

The 2024 heatwave in Sindh province produced official figures of at least 568 heat-related deaths and nearly 8,000 hospitalizations, with temperatures reaching 49°C. Karachi itself recorded 47.2°C, alongside night temperatures that stayed above 32.5°C, denying residents the overnight cooling that usually provides some physiological recovery. Twelve-hour power cuts, a routine feature of Karachi summers, turned homes without backup cooling into heat traps precisely when residents needed relief most.

Amnesty International's 2025 review of the crisis found that more than 95% of heat-related fatalities during the period were recorded under other diagnoses, dehydration-induced organ failure, cardiac arrest, rather than being coded as heat deaths. The same review found that Pakistan's civil registration system frequently only pursues formal death registration when a property dispute or other legal necessity requires it, which means large numbers of heat deaths, particularly among laborers and homeless residents, never enter the official count at all.

A pattern that repeats each summer

This is not a single-year anomaly. During the 2022 heatwave, official reporting counted only 56 heat-related deaths in Sindh, while Edhi Foundation morgue records for the same period suggested a toll far higher. Regional data collected across South Asia estimates that Pakistan and India combined recorded more than 3,500 heat-related deaths in 2015 alone, a scale that predates the more recent, more intense heat seasons.

Academic modeling of Karachi specifically links the rising death toll to three compounding factors: population density, air pollution, and the urban heat island effect layered on top of already extreme regional temperatures. The population most affected skews toward outdoor laborers and older residents, groups with the least capacity to escape heat exposure during power outages.

Why infrastructure failure changes the emergency response calculation

In most heat mortality frameworks, planners assume some baseline level of mechanical cooling access. Karachi's recurring grid failures during heatwaves break that assumption at exactly the moment it matters most. This means the response burden shifts disproportionately onto field-level intervention: cooling shelters, mobile medical response, and equipment that does not depend on the electrical grid functioning.

For exertional and classic heat stroke alike, the treatment window is short and mechanical. Cold water immersion cools the body at roughly 0.35°C per minute, close to ten times faster than wet towels or ice packs, and the Korey Stringer Institute's dataset of over 401 documented exertional heat stroke cases shows a 100% survival rate when core temperature drops below 40°C within 30 minutes of collapse. None of that depends on air conditioning being available. It depends on cooling equipment and water being present at the point of collapse.

Equipment that does not wait for the grid

A deployable, grid-independent immersion tub is one of the few interventions that functions identically whether the power is on or off. Kollder deploys in under 2 minutes by a single responder, on any terrain, giving field medical teams, disaster response organizations, and municipal emergency services a way to run the Cool First, Transport Second protocol even when the infrastructure around them has failed. More at kollder.com/#contact.

Karachi's Heat Crisis: What Grid Failure and Undercounted Deaths Reveal

The scale of the problem

A pattern that repeats each summer

Why infrastructure failure changes the emergency response calculation

Equipment that does not wait for the grid

Further reading