Firefighters wear Personal Protective Equipment (PPE) for protection from environmental hazards. However, due to the layers of protective functions, the PPE inevitably adds excessive weight, bulkiness, and thermal stress to firefighters. This study investigated the adverse impact of wearing PPE as an occupational stressor on the firefighter’s cognitive functioning. Twenty-three firefighters who had been involved in firefighting at least for 1 year were recruited. The overall changing trend in the firefighter’s cognitive functioning (short-term memory, long-term memory, and inductive reasoning) was measured by the scores of three standardized cognitive tests at the baseline and the follow-up, after participating in a moderate-intensity physical activity, wearing a full ensemble of the PPE. The study findings evinced the negative impact of the PPE on the firefighter’s cognitive functioning, especially in short-term memory and inductive reasoning. No significant influence was found on the firefighter’s long-term memory. The results were consistent when the participant’s age and BMI were controlled. The outcomes of the present study will not only fill the gap in the literature, but also provide critical justification to stakeholders, including governments, policymakers, academic communities, and industry, for such efforts to improve human factors of the firefighter’s PPE by realizing the negative consequences of the added layers and protective functions on their occupational safety. Study limitations and future directions were also discussed.

Abstract
 I. Introduction
 Ⅱ. Methods
  1. Recruitment
  2. Procedures
  3. Validation of cognitive tests with control group
  4. Data analysis
 Ⅲ. Results
  1. Participant profiles
  2. Baseline cognitive abilities
  3. Pre-post score comparisons on cognitive tests
 Ⅳ. Discussion
 Ⅴ. Conclusion
 References

• Juyeon Park(Dept. of Design and Merchandising, Colorado State University) Corresponding author