Impact of heat exposure on workers' health and safety: a scoping review.

Several studies have synthesised the health impacts of occupational heat exposure, yet previous reviews were limited in scope and only focused on specific diseases, high-risk industries or selected countries. This scoping review aimed to summarise global epidemiological evidence on health outcomes associated with occupational heat exposure, examine factors that may modify heat-health associations among workers and identify knowledge gaps to inform the development of more effective jurisdiction-specific heat policies.A search strategy reflecting heat, worker and health was applied to Ovid MEDLINE, Ovid EMBASE, CINAHL and Web of Science, and grey literature of EuropePMC, ProQuest and SafetyLit, to retrieve studies investigating associations between occupational heat exposure and illness and injury. Studies were independently reviewed by two reviewers to assess eligibility. A narrative synthesis approach was used to compare, contrast and synthesise the most relevant findings.This review included 92 studies that estimated associations between heat and various health outcomes, including workplace illness and injury, heat-related illness and deaths, kidney diseases, cardiovascular diseases, cancer, abnormal bone mineral density, skin diseases, eye diseases, infertility and mortality. The included studies presented conflicting evidence on heat-health associations: some observed stronger risks with rising temperatures, some observed smaller positive or reduced risks at extreme temperatures and others reported no associations. The discrepancies may be explained by differences in heat measurements and outcome ascertainments, methodological limitations, geographical variations and the varying impacts of demographic, work-related and individual factors.Jurisdiction-specific heat policies are needed to protect workers from acute and chronic health conditions.