Independent and interactive effects of thermal stress and mental fatigue on manual dexterity

Many occupations and sports require high levels of manual dexterity under thermal stress and mental fatigue. Yet, multistressor studies remain scarce. We quantified the interactive effects of thermal stress and mental fatigue on manual dexterity. Seven males (21.1 ± 1.3 yr) underwent six separate 60-min trials characterized by a combination of three air temperatures (hot, 37°C; neutral, 21°C; cold, 7°C) and two mental fatigue states (MF, mental fatigue induced by a 35-min cognitive battery; no-MF, no mental fatigue). Participants performed complex (O’Connor test) and simple (hand-tool test) manual tasks pre- and posttrial to determine stressor-induced performance changes. We monitored part…