2036.0 - Operational Fatigue and Sleep Loss in the Fire Service: Physiological Findings from Wearable Biometric Monitoring
Program: Occupational Health and Safety
Session: Poster Competition for Research and Practice in Occupational Health & Safety (I)
Authors: Michael Wininger, Kaakpema Yelpaala, Debbie Humphries, Alyse Sabina
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Abstract
Introduction
Firefighters face extended shifts and frequent night calls, placing them at elevated risk of sleep disruption and fatigue. This prospective observational project investigated how demanding shift schedules and operational workloads influence sleep architecture and recovery.
Methods
Firefighters from a single fire department (n=200) were recruited to continuously wear a biometric device tracking heart rate, sleep stages, and additional physiological indicators for 39 days. Biometric data was then merged with 911 call data and staffing records. Correlation matrices were developed to compare relationships between workload and measured biometric data. Subsequently, a random forest model was developed and validated to predict firefighters’ biometric response to given workload.
Results
Findings revealed substantial deficits in slow wave and REM sleep during consecutive duty nights, with the greatest reductions observed in personnel assigned to high-volume ambulance units. There were significant differences in restorative sleep (Slow wave and REM) between on-shift (157.0 ± 58.2 minutes) versus off-shift (192.0 ± 60.9 minutes), P < 0.001.) There were also significant correlations between elevated night 911 call frequency, diminished restorative sleep (r = -0.75), increased resting heart rate (r = 0.68) reduced heart rate variability (r =-0.53) - factors closely tied to cognitive performance and overall well-being.
Conclusions and Recommendations
The predictive modeling framework validated the ability to forecast fatigue levels from real-time operational conditions, enabling data-driven interventions that target workload redistribution and strategic scheduling. Recommended solutions include later shift start times, alternative work cycles, and dynamic resource deployment. These measures aim to preserve firefighter health, maximize operational effectiveness, and promote sustainable workforce policies by mitigating the harmful consequences of chronic sleep disruption.