Prolonged facemask use in the heat worsens dyspnea without compromising motor-cognitive performance

Background: Within the context of the COVID-19 pandemic, the WHO endorses facemask use to
limit aerosol-spreading of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV
-2). However, concerns have been raised regarding facemask-associated dyspnea, thermal distress
and self-reported impairment of cognition. Accordingly, we tested how facemask-use affects
motor-cognitive performances of relevance for occupational safety. We hypothesized that mask
use would affect cognitively dominated performances and thermal discomfort, but not alter
whole-body thermal balance.
Methods: Eight participants completed a facemask and a barefaced (control) trial, in
a counterbalanced order, in 40°C and 20% humidity conditions. Motor-cognitive performance,
physiological (rectal, mean skin and local facial temperatures) and perceptual (thermal comfort
and dyspnea) measures were assessed at baseline and following 45 min of light work (100 W).
Results: Perceived dyspnea was aggravated with prolonged facemask use (p = 0.04), resulting in
36% greater breathlessness compared to control. However, no other differences were observed in
motor-cognitive performance, physiological strain, or thermal discomfort.
Conclusions: Contradicting negative self-reported impacts of facemask-use, only dyspnea was
aggravated in the present study, thereby reinforcing global recommendations of mask use, even
in hot environments. (Funded by: European Union’s Horizon 2020 research and innovation
program under the grant agreement No 668786).