Effect of a Simulated Mine Rescue on Physiological Variables and Heat Strain of Mine Rescue Workers

Objective: To describe physiological responses of mine rescuers during a simulated mine emergency. Methods: Body-worn monitors (n = 74) and core temperature (Tc) capsules (n = 54) assessed heart rate (HR), respiration rate (RR), energy expenditure (EE), oxygen consumption (V. O2), Tc and skin temperature (Tskin), by team position and task. A multivariate analysis was performed with team positions, tasks, and measures as factors. Results: HRHRmean and HRpeak were 78.6% and 94.5%, respectively, of predicted maximum heart rate. Arduous labor tasks elicited higher HR, RR, and V. O2mean than casualty care. Captains exhibited lower HRmean, HRpeak, RR, RRpeak, V. O2mean, Tc, and Tskin compared with other positions. Tc mean exceeded 38.6 8C (n = 14 recorded T c > 39 8C). Conclusions: Captains' physical loading and heat stress were lowest. Nonetheless, all tasks and positions induced high physical load and heat strain.