Sudden cardiac death in the fire service

Fire scenes are unpredictable environments characterized by numerous dangers: loud noise, high temperatures, flames, smoke and its toxic components, and potential instability of the affected structures among others. Accordingly, firefighting is widely recognized as a hazardous profession that can result in burns, trauma, smoke inhalation and other myriad injuries. Nonetheless, in the USA, the leading cause of duty-related fatalities among firefighters is cardiovascular disease (CVD). In fact, sudden cardiac death (SCD) has consistently accounted for approximately 45% of all on-duty firefighting deaths in the USA since at least the 1970s [1–3]. To understand why SCD is the predominant cause of on the job death, one must examine the physical demands of firefighting and the resulting psychophysiologic responses. Structural firefighting requires the performance of activities combining static and aerobic exertion: stair and ladder climbing (with simultaneous heavy materials handling), forcible entry, search and rescue for victims, cutting and chopping to provide ventilation of the building and advancing charged hoselines to attack and suppress the fire [1,3,4]. Additionally, these essential duties are performed while wearing encapsulating protective clothing that weighs ≥25kg, plus tools, which exacerbate the heat load and metabolic demands of firefighting. Based on several studies, expert consensus has concluded that firefighters require a minimum aerobic capacity of 42 ml·kg−1·min−1 (or 12 metabolic equivalents (METs)) to safely perform all of their essential tasks [1,3].