An exploratory survey assessing the determinants of heat stress and heat strain in the Canadian mining industry from the worker's perspective.

With mines extending deeper and rising surface temperatures, workers are exposed to hotter environments. This study aimed to characterize heat stress and strain in the Canadian mining industry and evaluate the utility of the Heat Strain Score Index (HSSI), combined with additional self-reported adverse health outcomes. An exploratory web-based survey was conducted among workers ( = 119) in the Canadian mining industry. The survey included 74 questions on workers' risk perception, strategies for heat stress management, and the HSSI-a validated tool to classify workplace heat stress based on various workplace factors and indicators of heat strain. Most workers reported that heat stress is an occupational hazard associated with their duties and tasks (89%). Based on the HSSI, 22% of respondents were classified as high risk, 42% at moderate risk, and 36% at low risk for heat stress and heat strain. Those with higher HSSI scores self-reported more heat-related adverse signs and symptoms with a higher prevalence of self-reported heat-related illness ( < 0.01). Despite workers reporting various self-initiated practices (e.g., drinking water) and management-enforced heat mitigation practices (e.g., rest breaks), many workers reported still having experienced signs or symptoms of heat stress (86%) and heat-related illnesses (37%). The study found elevated heat stress and strain levels among a sample of workers in the Canadian mining industry despite workers employing various heat-mitigating strategies. Heat stress management programs considering mining-specific factors and challenges are needed to safeguard worker health and safety.