The capacity for rural fire agencies to respond during an emergency incident is influenced by the operational readiness of the firefighters. Occupational and environmental challenges such as high ambient temperatures and restricted sleep opportunities, can impact an individual’s capacity to perform their fireground work tasks effectively, efficiently and safely. The current project examined aspects of firefighter performance under conditions of high ambient temperatures (33 degrees) and sleep opportunities’ of four hours (awake/hot condition) compared to eight hour sleep opportunities and ambient temperature of 20 degrees (control condition).  The aim of the present study was to provide agencies with an evidence-base on which to formulate risk management plans for rural firefighters on deployment. Firefighters in the awake/hot condition reported higher levels of fatigue, lower levels of alertness and reduced motivation to perform compared to firefighters in the control condition. Reaction times were slower and more lapses in attention occurred in the awake/hot condition. Physical performance was impacted most severely in tasks that were high intensity (e.g., raking) and frequent (e.g. lateral repositioning).  There were no differences in firefighters’ heart rate or perceived exertion levels despite differences in physical performance.  The impaired physical work may reflect firefighters’ higher fatigue and diminished motivational levels or a conscious decision to pace their efforts to a set level of exertion.  The findings from this work will allow agencies to better understand and predict the degree to which operational readiness may be impaired by certain external factors and thus better manage the health, safety and operational risks.