Search for: All records

The purpose of this study is to investigate the combined impact of mask-wearing on cognitive performance and risk-taking behaviors. Participants were divided into a control group (N=24) without and an experimental group (N=27) with a surgical mask. Both groups completed the tasks in a warm environment (30 oC) where the conditions can reduce cognition and decision-making as well. These conditions are common in indoor spaces without sufficient air conditioning during a heat wave. Cognition and risk-taking behaviors were assessed using computerized tests. Results showed that mask-wearing in warm environment did not negatively impact cognitive performance, nor did it increase risk-taking behavior as the concept of risk compensation predicts, even when the CO2 concentration was elevated to approximately 29,000 ppm on average inside the mask. On the contrary, mask-wearing participants showed less risk-taking behaviors, slightly better response inhibition and better short-term memory. These results do not support previous findings suggesting that even a moderately increased indoor CO2 level can reduce cognition. We hypothesize that human adaptation effects (due to mask-wearing on a daily basis) make people less vulnerable to the adverse environment (i.e., excessive air temperature and CO2 levels), which will be investigated in the future studies. 

The objective of this study is to assess the effectiveness of wearable cooling in improving thermal comfort for a warm environment that would become prevalent due to more frequent extreme weather events, especially when air conditioning is not accessible for many developing countries. The experiment was conducted in an environment room with air temperature maintained at 31 °C and relative humidity at 55%. The study tested 30 participants using a wearable cooling device at the upper back location, while another 30 had no local cooling as the control group. Participants’ thermal comfort, thermal sensation and other metrics were assessed three times for a test session. The clothing insulation was 0.36 clo to simulate summer attire. The results showed significantly lower average local and whole-body thermal sensation for the participants with the wearable cooling device than the control group by considering all the votes during the entire session. Compared to the baseline, in particular, the local cooling group indicated a significant reduction in local thermal sensation for all three times of self-evaluation. Nevertheless, the reduction in overall thermal sensation occurred right after the local cooling was applied. Such a significant reduction was not observed after a while and then emerged again during the test, indicating an interactive phenomenon involving thermal adaptation and comfort restoration which will be investigated in the future.