ISO 8025:2024

Overview

ISO 8025:2024 - "Ergonomics of the thermal environment - Management of working conditions in hot environments" provides a structured, practical framework for identifying, assessing and managing heat-related risks in the workplace. Applicable to both indoor and outdoor work, the standard adopts a severity-based approach: control measures and medical supervision are specified according to the exposure class and potential health effects. ISO 8025 supports occupational safety and health practices and integrates with broader management systems.

Key topics

• Multi-stage exposure assessment - a practical procedure to manage hot workplaces, including:
  • Stage 1 (screening) to identify situations likely to cause heat stress;
  • Stage 2 (observation) for qualitative review and simple mitigation;
  • Stage 3 (analysis) for detailed assessment and corrective actions;
  • Use of a Thermal Exposure Form (TEF) to document conditions.
• Exposure classification (EC 1–6) - work situations are classified by predicted thermal strain using PMV and a duration limit (D). EC 1 indicates thermal comfort (-0.7 < PMV < 0.7); EC 6 indicates an immediate thermal constraint (D ≤ 30 min).
• Control measures - practical controls addressing work organization, air temperature, humidity, thermal radiation, air velocity, clothing, workload, rehydration, rest/recovery and acclimatization.
• Medical surveillance and training - guidance on initial and periodic medical evaluation, personal monitoring, worker instruction and employer information.
• Use of heat indices and models - guidance on applying established indices (for example WBGT, PHS, PMV) and metabolic-rate considerations during assessment (symbols and methods referenced).

Applications

• Risk assessment and management for industries with significant heat exposure: manufacturing, foundries, construction, agriculture, utilities, emergency response and outdoor maintenance.
• Development of workplace heat-control programs: scheduling, rest/recovery policies, hydration strategies, PPE/clothing selection, acclimatization plans.
• Basis for occupational-health protocols: tailored medical surveillance, worker training materials, and documentation using the TEF.
• Integration into occupational health & safety management systems to reduce heat-related illness, maintain productivity and improve safety.

Who should use this standard

• Occupational health & safety professionals, ergonomists and industrial hygienists
• Safety managers and HR/medical staff responsible for worker health surveillance
• Facility and operations managers in heat-exposed industries
• Consultants preparing heat-stress assessments, training, or emergency response plans

Related standards

• ISO 15265 - Risk assessment strategy in thermal working conditions
• ISO 7933 - Predicted heat strain and exposure duration (reference for D)
• ISO 7730 - Thermal comfort (referenced for PMV ranges)
• ISO 45001 - Occupational health & safety management systems (for integration)

Keywords: ISO 8025 2024, ergonomics of the thermal environment, heat stress, hot workplaces, thermal exposure, WBGT, PMV, medical surveillance, occupational health and safety.