Thermoregulatory and cognitive responses to ambient temperature under resting and exercise conditions

Ambient temperature is associated with human thermoregulation and may relate to cognitive performance, but the effects of mild cold and moderate heat, which are more representative of daily environments, remain insufficiently understood. This study examined the thermoregulatory, perceptual, and cognitive responses during passive rest and moderate-intensity exercise. Forty-eight participants were randomly assigned to cold (10°C), moderate (22°C), or hot (32°C) conditions and completed separate resting and exercise sessions at their assigned temperature. Core temperature (Tcore), mean skin temperature (Tsk), thermal comfort (TC), and cognitive performance were assessed before and after a 1-h intervention using the Attention Network Test (ANT) and Stop-Signal Task (SST) under controlled relative humidity. Under resting conditions, Tsk decreased in the cold group without a corresponding change in Tcore, whereas both Tsk and Tcore increased in the hot group. TC was lower in the cold and hot groups than in the moderate-temperature group during the rest session. No significant ambient temperature × time interactions were detected for the ANT or SST outcomes, although significant main effects of time were observed for selected measures. Exploratory post-hoc comparisons showed cold-related reductions in accuracy under specific cue conditions, and heat-related declines in stop-accuracy with increased stop-signal reaction time/stop-accuracy, while stop-signal delays shortened in both cold and hot groups after sitting. These findings suggest a potential link between thermal exposure and cognitive changes at rest. During exercise, thermoregulatory and perceptual responses remained evident, but no significant temperature × time interactions were observed for cognitive outcomes. Reaction times and accuracy on both tasks were largely preserved across conditions. The pattern of cognitive responses to temperature differed at rest and during exercise. Overall, mild cold and moderate heat produced clear thermoregulatory and perceptual responses, whereas cognitive responses were varied across tasks and conditions.