AT some point this summer, somewhere along the value chain, output fell. Nobody logged it as a climate loss. It was absorbed instead as a missed delivery window, a spike in afternoon defects, an absenteeism figure that went unexamined. The cause was heat, and most Pakistani businesses are neither measuring it nor pricing it.

The backdrop is no longer deniable. This spring’s pre-monsoon heatwave pushed temperatures across the region above 46 degrees Celsius, an event that scientists at World Weather Attribution found was made roughly three times more likely by climate change. The human toll is systematically undercounted: during Karachi’s June 2024 heatwave, the Edhi Foundation received 568 bodies in five days, against a normal average of about 40 a day, while the local government attributed just 13 deaths that month to the weather. If deaths on this scale can go unrecorded, quieter losses of output and productivity certainly do.

Corporate Pakistan is not ignoring climate change. CERB’s case study on business climate readiness found companies working seriously on transition risk: decarbonisation targets, renewable procurement, positioning for a low-carbon economy. All of this is necessary, and investors reward it. But the same study found very few businesses with any grasp of physical risk — the direct hit a changing climate delivers to assets, operations and people. Almost none had a considered response to the most immediate threat of all, which is what heat does to worker health, safety and productivity. In the world’s most climate-affected country, businesses prepare for the climate risk set out in regulation and miss the one unfolding on the ground. Part of the reason is that heat, unlike a flood, announces nothing. It leaves no wreckage to photograph and no claim to file, only a slow leak of hours and output that is never traced back to its cause.

These are not sustainability numbers; they are operating numbers. The WHO and WMO report that “worker productivity declines by two to three per cent for every degree above 20°C”. The ILO finds that heat stress generally sets in above 35°C in humid conditions, and international benchmarks now call for outdoor work to stop when wet-bulb globe temperature exceeds 32.1°C. Karachi crossed 47°C in June 2024. Globally, heat stress is projected to erase the equivalent of 80 million full-time jobs by 2030, and Southern Asia stands to lose up to 5pc of working hours, placing it among the worst affected regions anywhere. No business would tolerate an unexamined 5pc hit to capacity from any other cause.

Pakistan’s heat problem is a business problem.

Once businesses begin tracing these risks along the value chain, industry-specific patterns emerge. Take textiles, the country’s largest export earner. The exposure starts in the field, where extreme heat during flowering cuts cotton yields before a single bale reaches the mill. It continues through ginning and spinning units sited in some of the hottest districts in Punjab and Sindh, and on to stitching floors where piece-rate workers, paid by output rather than hours, have every reason to work through heat stress instead of resting it out. Defects and accidents climb with the temperature, absenteeism follows, and load-shedding arrives just as cooling demand peaks. By the time the shipment leaves late, the invoice records everything except the cause.

So what?

None of this requires waiting for the government or for a re­gulatory requirem­ent. It requires businesses to understand and measure their own vulnerability to rising temperatures. A climate risk assessment maps operati­o­­ns and suppliers agai­nst physical climate scenarios, identifies where heat, flooding and water stress leave them most exposed, and quantifies that vulnerability so it can be managed like any other risk. The interventions that follow are mostly unglamorous and affordable: shaded and cooled work areas, adjusted shift timings and heat protocols, supplier diversification and more resilient infrastructure. But none of them can be targeted until a business knows where its value chain is actually exposed, and the assessment is where that work has to start.

Transition risk is real and it deserves the attention it gets. But the more immediate threat needs no modelling: heat arrives every summer and it is already costing lives, hours and output. The companies that stress-test their exposure now will be better placed to keep delivering when the next heatwave sets records. For everyone else, the losses will not stop; they will simply keep appearing under other names.

The writer is a senior manager for sustainability at the Pakistan Business Council’s Centre of Excellence in Responsible Business.

Published in Dawn, August 20th, 2026