The effects of temperature, sleep restriction, and physical activity on the sleep architecture and cognitive performance of volunteer firefighters during various simulation wildland fireground tours

The overall aim of this thesis was to investigate the interactions between firefighters’ sleep, ambient temperature, hydration status, and cognitive performance during simulated single and multi-day wildfire suppressions. These exact aims are addressed through four studies: 1. To assess the effect of ambient heat during day-(33-35°C) and night-time (23-25°C) exposures on firefighters’ sleep quantity and quality during a simulated multi-day wildfire suppression compared to thermoneutral temperatures (18-20°C; Study 1 -Chapter 4). 2. To quantify the effect of sleep restriction in either ambient heat with day- (33-35°C) and night-time (23-25°C) exposures or thermoneutral conditions (18-20°C) on firefighters’ sleep architecture during a simulated multi-day wildfire suppression compared to a control condition with normal sleep in temperate conditions (18-20°C; Study 2 –Chapter 5). 3. To examine the association between firefighters’ hydration status and cognitive performance during a simulated prolonged wildfire suppression shift in the heat (33-35°C) compared to thermoneutral temperatures (18-20°C; Study 3 –Chapter 6). 4. To examine the effect on cognitive performance of sleep restriction in either ambient heat with day-(33-35°C) and night-time (18-20°C) temperature changes or temperate conditions (18-20°C) during a simulated multi-day wildfire suppression compared to a control condition with full sleep opportunities in thermoneutral temperatures (18-20°C; Study 4 –Chapter 7).