Heat is erasing 4.1% of Bangladesh's garment factory revenue, according to a report carried by Fibre2Fashion, putting a hard commercial number on a climate risk that suppliers and buyers in the ready-made garment (RMG) sector have so far treated as an operational nuisance rather than a balance-sheet item.

The 4.1% revenue loss sits at the factory gate — the tier of the supply chain where Bangladesh's roughly four million garment workers cut, sew, finish and pack orders for European and North American brands. For an industry that competes on thin margins and volume reliability, a mid-single-digit revenue hit from ambient temperature alone reframes heat as a sourcing-cost variable on par with cotton prices, wage revisions and freight rates.

The mechanism is production-floor physics. Excessive heat reduces worker productivity on sewing lines, raises the risk of output shortfalls against delivery deadlines and pushes up energy costs as factories run cooling systems harder to keep floor conditions workable. The revenue erosion compounds at exactly the point where Bangladesh's competitive advantage is concentrated: high-volume, labour-intensive cut-make-trim capacity operating on tight lead times.

For sourcing directors, the commercial implication is direct. Bangladesh remains one of the largest apparel sourcing destinations globally, and a structural productivity drag of this scale means longer effective lead times, higher unit costs or greater risk of late shipments during the hottest months of the year. Buyers planning spring and summer order books — and those locking in capacity for peak-season deliveries — now need to price heat exposure into their Bangladesh allocations in the same way they price port congestion or energy costs.

The exposure also carries a compliance dimension. International buyers increasingly audit factory conditions against worker-safety and wellbeing standards, and excessive floor temperatures sit squarely in that frame. Heat-stress management — ventilation, hydration protocols, shaded rest areas, adjusted shift patterns — is moving from a welfare talking point to an audit-line item that suppliers must evidence. Factories that cannot demonstrate heat mitigation may find themselves flagged in buyer compliance scoring, with consequences for order placement.

The financial exposure lands hardest on smaller and mid-sized factories that lack the capital to retrofit cooling infrastructure or redesign production scheduling around peak-heat hours. Larger, vertically integrated suppliers with investment capacity can absorb some of the drag through engineered ventilation and energy-efficient systems. That differential is likely to sharpen the consolidation already under way in the Bangladesh supplier base, as buyers concentrate volume with factories that can guarantee output consistency year-round.

The Fibre2Fashion report, which surfaced the 4.1% figure, does not disaggregate the loss by product category, factory size or region within Bangladesh. That gap matters for buyers: heat exposure will vary significantly between a Dhaka-area woven-garment unit and a knitwear plant in Gazipur or Chattogram, and allocation decisions need facility-level data rather than a national average.

The sourcing decision this news forces is straightforward but uncomfortable. Brands committed to Bangladesh for its scale, cost position and increasingly mature compliance infrastructure must now treat climate-driven productivity loss as a live variable in their 12-month capacity planning. That means building heat-adjusted lead times into order calendars, prioritising suppliers with demonstrated thermal-management investment, and opening a due-diligence line on factory cooling and heat-stress protocols during compliance audits. Factories, for their part, face a capital-allocation choice: invest in heat mitigation now to defend revenue and audit standing, or absorb an ongoing 4.1%-scale drag on earnings in an industry where few suppliers can afford it.