The Impact Of Rapid Heat Stress On Neuropsychological Status Among Firefighters

PURPOSE: The present experiment sought to measure the impact of rapid heat stress following exercise while wearing firefighter personal protective equipment (PPE) on generalized neuropsychological status. Rapid heat stress is a type of uncompensable heat stress where individuals wearing fully encapsulated PPE rapidly increase in core temperature (≥ 0.04 °C/min). The Repeatable Battery for Neuropsychological Status (RBANS) measures five cognitive domains: immediate memory, visuospatial perception, expressive language functioning, attention, and delayed memory. Our previous research has demonstrated that similar conditions have resulted in specific electroencephalography (EEG), cerebral oxygenation, reaction time, and response inhibition changes. No studies have sought to determine the generalized neurocognitive status of firefighters following rapid heat stress. Here, we hypothesized that rapid heat stress would cause negative changes in the five cognitive domains. METHODS: Fifteen male participants performed a steady-state exercise walking treadmill protocol in an environmental chamber (35 °C; 50% humidity) in PPE until completing the protocol, reaching a core temperature of 39 °C, or a volitional maximum. The five domains measuring neurocognitive status were measured pre- and post-heat stress using the RBANS. The RBANS provides an index score for each domain based on the performance of the RBANS tasks. RESULTS: There were no changes (p > 0.05) in the five domains of neurocognitive status (Immediate memory: Pre: 86.6 ± 11.9, Post: 89.6 ± 10.4; Visuospatial Perception: Pre: 110.2 ± 7.7, Post: 109.3 ± 14.2; Expressive Language Functioning: Pre: 98.6 ± 12.7, Post: 100.8 ± 12.3; Attention: Pre: 101.3 ± 14.5, Post: 104.4 ± 16.3; Delayed Memory: Pre: 92.3 ± 17.9, Post: 89.7 ± 18.0) when comparing pre- and post-heat stress values. CONCLUSION: Immediate memory, visuospatial perception, expressive language functioning, attention, and delayed memory were not impacted by rapid heat stress. Supported by: Collaborative Intramural Research Program (CIRP) LSU Health Shreveport