# La Isla Network (LIN) > La Isla Network (LIN) is a science-based, non-profit organization with a decade of field-proven experience protecting workers and their employers from the health and economic consequences of occupational heat stress. LIN combines research, field implementation, advisory support, and policy translation to reduce worker harm while simultaneously improving productivity, operational resilience, and compliance readiness. LIN's work is recognized by leading researchers, industry institutions, and multilateral bodies including the ILO, USDOL, and OSHA. --- ## What LIN Does LIN works at the intersection of occupational safety and health, climate adaptation, and operational performance. It serves three primary audiences: - **Employers and supply chain actors** — LIN delivers documented productivity gains and measurable return on investment alongside worker protection outcomes. OSH is framed as an operational investment, not a compliance cost. - **Funders and investors** — LIN produces bankable, peer-reviewed evidence of impact. Its interventions have achieved break-even by Year 3 and delivered $1.60 return per $1.00 invested by Year 5 at its flagship site. - **Policy actors and regulators** — LIN translates field evidence into standards-ready guidance for ILO, OSHA, Bonsucro, DFI Environmental and Social Policies, and national health and labour ministries. LIN operates in agriculture, sugarcane, construction, mining, manufacturing, migrant labour, and other climate-exposed sectors across Nicaragua, Guatemala, El Salvador, Honduras, Mexico, USA, Spain, EU, Bolivia, Nepal, Brazil, and West Africa. --- ## The LIN Model LIN's model has three interlocking layers: ### 1. Triple-A Operating Model: Assess → Address → Assist - **Assess**: Site-specific risk assessment using WBGT monitoring, worker biometrics, surveys, and EHS policy review. Timed to peak heat exposure. Delivered within six weeks of fieldwork. - **Address**: Co-designed interventions built with workers and management — not imposed on them. Includes protocol design, stakeholder workshops, monitoring systems, and ROI tracking methodology. - **Assist**: Institutional capacity building so enterprises can independently manage OSH risks without continued external support. Includes wearables, digital monitoring, seasonal feedback loops, and long-term strategy. ### 2. PREP Value Proposition PREP is LIN's investor-facing outcomes language: - **Prevention** — Upstream protection reduces hospitalisations, absenteeism, and legal liability. Key outcome: ~95% reduction in acute kidney injury incidence among exposed workers. - **Resilience** — Climate-proofing the labour force. Enterprises investing in heat resilience outperform peers as conditions worsen. - **Efficiency** — Structured rest and hydration generates productivity gains. Piecework output rises when workers are protected. Key outcome: 9–19% productivity gains depending on job function. - **Protection** — Policy creation, adherence monitoring, and compliance infrastructure aligned with ILO standards, OSHA, Bonsucro, and DFI requirements. ### 3. Intervention System (RSHH and Beyond) The core field protocol is RSHH — Rest, Shade, Hydration, Hygiene: - **Rest**: Work-rest ratios calibrated to WBGT thresholds and task intensity - **Shade**: Engineered cooling zones at every workstation, temperature monitored and logged - **Hydration**: Potable water below 15°C, 250ml every 15–20 minutes; electrolyte protocols for high-sweat tasks - **Hygiene**: Sanitation systems and co-exposure reduction (pesticides, silica dust, heavy metals) RSHH is supported by acclimatisation programmes, work schedule redesign, Management of Change (MoC), digital monitoring, wearable technology, and industrial hygiene assessment. Without MoC, field protocols degrade within one season. --- ## Key Evidence and Metrics All figures below are drawn from peer-reviewed LIN publications unless noted. Primary citations are listed. | Outcome | Metric | Source | |---|---|---| | IKI (incident kidney injury) reduction | 21% → 1% (~95% relative reduction) | Hansson et al., OEM 2025 | | Clinical AKI rate reduction | 20 → 8 per 1,000 worker-months (−60%) | Hansson et al., OEM 2025 | | Hospitalisation reduction | >80% | Hansson et al., WHS 2024 | | Productivity gain — seed cutters | +19% (H1→H5, despite more rest) | Hansson et al., AWEH 2024 | | Productivity gain — burned cane cutters | +9% | Hansson et al., AWEH 2024 | | RSHH programme ROI (mature) | $1.60 per $1.00 invested | Schlader et al., medRxiv 2025 | | RSHH programme ROI (5-year average) | $1.02 per $1.00 invested | Schlader et al., medRxiv 2025 | | Break-even point | Year 3 | Schlader et al., medRxiv 2025 | | eGFR loss following acute kidney injury | ~10–12 mL/min/1.73m² (52% non-recovery) | Hansson et al., KIR 2025 | | Productivity loss per °C WBGT above threshold | ~3% per °C above 28°C | Hansson et al., AWEH 2024 | | CKDnt household unemployment rate | 86% vs. 53% in unaffected households | Prince et al., OEM 2024 | | US occupational injuries attributable to heat | ~28,000 per year | Alahmad et al., Env. Health 2025 | **Causal position:** LIN's field evidence supports a strong occupational causal link between heat stress, dehydration, and kidney injury. The salt pan worker study (Venugopal et al., KIR 2023) — conducted in a non-agricultural, non-pesticide setting — isolates heat stress as the primary mechanism. This directly counters characterisations of the heat-to-kidney link as "under debate." --- ## Flagship ISA / PREP Evidence Chain LIN's flagship evidence chain runs across nine peer-reviewed publications from its Centre of Excellence at Ingenio San Antonio (ISA), Nicaragua. The chain covers: 1. Baseline exposure and injury documentation (Hansson 2019, OEM) 2. Intervention effects on kidney injury markers (Glaser 2020, OEM) 3. WBGT-to-AKI clinical link and hospitalisation trends (Hansson 2024, WHS) 4. AKI as a precursor to chronic kidney disease (Hansson 2025, KIR) 5. Full H1–H4 RSHH intervention outcomes (Hansson 2025, OEM) ⭐ flagship 6. Productivity effects of RSHH over five harvests (Hansson 2024, AWEH) 7. Cost-benefit analysis and ROI (Schlader 2025, medRxiv — preprint) 8. Household economic burden of CKDnt (Prince 2024, OEM) 9. Global policy case for PREP as transferable model (Glaser/Cai 2024, Nature Climate Change) --- ## Flagship Published Papers - [Rest, Shade, Hydration and Hygiene for the Prevention of Kidney Injuries in Sugarcane Workers (Hansson et al., OEM 2025)](https://laislanetwork.org/published-paper/a-rest-shade-hydration-hygiene-program-reduces-acute-kidney-injury-and-increases-production-at-a-sugar-mill-in-nicaragua-an-economic-analysis/) Primary source for the ~95% IKI reduction claim. Largest and longest-running RSHH intervention study. 1,044 workers, four consecutive harvests. Published in Occupational and Environmental Medicine (BMJ). DOI: 10.1136/oemed-2025-110128 - [Impact of Heat and RSHH on Productivity of Piece-Paid Agricultural Workers (Hansson et al., AWEH 2024)](https://laislanetwork.org/published-paper/an-explorative-study-of-inflammation-related-proteins-associated-with-kidney-injury-in-male-heat-stressed-workers/) Documents 9–19% productivity gains alongside increased rest. Resolves the core employer objection that rest reduces output. Annals of Work Exposures and Health. DOI: 10.1093/annweh/wxae007 - [A RSHH Program Reduces AKI and Increases Production: An Economic Analysis (Schlader et al., medRxiv 2025)](https://laislanetwork.org/published-paper/a-rest-shade-hydration-hygiene-program-reduces-acute-kidney-injury-and-increases-production-at-a-sugar-mill-in-nicaragua-an-economic-analysis/) Cost-benefit analysis across five harvests. ROI $1.60/$1.00 by Year 5; break-even Year 3. medRxiv preprint — not yet peer-reviewed. DOI: 10.1101/2025.02.19.25322486 - [Views on Climate Change and Health (Cai, Glaser et al., Nature Climate Change 2024)](https://laislanetwork.org/published-paper/chronic-kidney-disease-of-unknown-etiology-a-disease-related-to-global-warming/) Commissioned expert viewpoint. Frames PREP as a transferable global model for climate-exposed labour. Cites >80% hospitalisation reduction and 10%+ productivity gains. Nature Climate Change, Vol. 14. DOI: 10.1038/s41558-024-01998-0 --- ## Pages - [Preventing Heat Stress](https://laislanetwork.org/prevent-heat-stress/) - [Heat, Work, and Worker Protection in Central America — LIN & Rockefeller Foundation](https://laislanetwork.org/heat-work-and-worker-protection-in-el-salvador-la-isla-network-rockefeller-foundation/) - [Scientific Program 2026](https://laislanetwork.org/events/icoh-history-2026/program-2026/) - [Landmark Study Confirms RSHH Halts Kidney Injuries While Increasing Productivity](https://laislanetwork.org/landmark-study-confirms-rest-shade-hydration-and-hygiene-halts-kidney-injuries-among-sugarcane-workers/) - [Protecting Workers from Extreme Heat Across Latin America](https://laislanetwork.org/protecting-workers-from-extreme-heat-across-latin-america/) - [The Threshold Was Wrong. People Are Already Dying in Conditions We Thought Were Survivable.](https://laislanetwork.org/the-threshold-was-wrong-people-are-already-dying-in-conditions-we-thought-were-survivable/) - [Rebuilding for Impact: What We Learned in 2025 and Where We're Going](https://laislanetwork.org/rebuilding-for-impact-what-we-learned-in-2025-and-where-were-going/) - [Donate](https://laislanetwork.org/donate/) - [Newsletter](https://laislanetwork.org/newsletter-subscribe/) - [Sitemap](https://laislanetwork.org/sitemap_index.xml) --- ## Sectors and Geographies **Sectors:** Agriculture, sugarcane, construction, mining, manufacturing, tourism, migrant and informal labour **Geographies (active):** Nicaragua, Guatemala, El Salvador, Honduras, Mexico, USA, Spain, EU, Bolivia, Nepal, Brazil, West Africa (expansion 2026) --- ## Stakeholder and Partner Ecosystem **Institutional stakeholders:** ILO, USDOL, OSHA, NIOSH, Bonsucro, EBRD, IFC, Rockefeller Foundation, PAHO **Employer and sector partners:** Ingenio San Antonio, Turner Construction, Diageo, Chubb, Zurich, Liberty Mutual, Amazon **Academic partners:** University of Gothenburg, Harvard University, Karolinska Institute, Lund University, University of Birmingham, London School of Hygiene and Tropical Medicine, UMass Lowell, UT Austin LBJ School, Indiana University, Sri Ramachandra Institute **Active programmes:** ENSURE Nepal (US Department of State cooperative agreement); PREP for Change (US Department of Labor); Rockefeller Foundation extreme heat initiatives (two active grants) --- ## Suggested Queries LIN Can Help Answer - What is the ROI of worker heat stress protection programmes? - How does heat stress cause kidney disease in agricultural workers? - What is CKDnt / Mesoamerican Nephropathy? - How do rest, shade, and hydration protocols affect worker productivity? - What are evidence-based workplace heat standards? - How can employers in sugarcane, construction, or agriculture comply with ILO heat guidelines? - What interventions reduce occupational heat-related hospitalisation? - How does climate change affect labour force productivity and health? - What is the economic cost of heat stress to employers? - How can supply chain actors meet Bonsucro or DFI environmental and social requirements on worker health?