Deaths of firefighters, new research and the need to address an existing problem


Circular: 2017HOC0203AD

Dear Brother/Sister

Deaths of firefighters, new research and the need to address an existing problem

New research funded by the British Heart Foundation

Please find attached an article from the journal Circulation which contains the contents of a major piece of independent research funded by the British Heart Foundation (BHF) which studied the relationship between cardiovascular attacks suffered by firefighters and operational activity.  The research report can also be read using this link

This circular brings attention to some of the key sections in the document.

Using sophisticated and a strict clinical methodology, the researchers have shown a clear link between the workload undertaken on the incident ground and the number of heart attacks amongst firefighters.

The report draws conclusions and makes recommendations with far-reaching implications and provides further evidence to a number of arguments and policy positions adopted and campaigned for by the Fire Brigades Union.

The report states:

“Cardiovascular events are the leading cause of death amongst firefighters and are responsible for approximately 45% of on-duty fatalities each year in the United States.  These deaths disproportionately cluster around fire-suppression duties”

Although the report brings attention to previous studies which show “the ongoing susceptibility to cardiac events in firefighters beyond the immediate post-exposure period”, the BHF study shows that risk is highest at the time of dealing with fires:

“Death from coronary artery disease was 12- to 136-times more likely to occur during or shortly after fire suppression than non-emergency duties. The hostile conditions of fire suppression include high ambient temperatures, extreme physical exertion, noxious air pollutants and psychological stress.”

The results of the study were assessed through monitored fire simulation training activity performed by 19 healthy non-smoking young adults (16 male, 3 female). The results of tests carried out during the simulation were marked and made a distinct impression on the researchers:

“Following a short exposure to fire simulation training, we demonstrate striking changes in physiological measures of cardiovascular function…

“The degree of thrombus formation demonstrated in healthy firefighters following a short fire simulation exposure is somewhat extraordinary.

The summary of the authors finding were:

“In conclusion, exposure to extreme heat and physical exertion during simulated fire suppression increases thrombogenicity, impairs vascular function and causes myocardial injury in healthy firefighters. Our findings suggest the pathogenic mechanisms to explain the association between fire suppression activity and acute myocardial infarction in susceptible firefighters.”

The striking results should be seen in the wider context as has been identified in the report: 

“Fire simulation exposure undoubtedly is not accurately representative of real-life fire suppression which is the main limitation of this study. In real-life fire suppression, the physiological stresses demonstrated in this fire simulation will undoubtedly be compounded by uncontrolled and higher ambient temperatures, multiple entries into the same fire and the potential psychological stress of attending an unknown and dangerous situation where one’s life and the lives of others are at risk.”

The Fire Brigades Union welcomes this research and notes that the report highlights that further work is required to examine some key issues, including:

  • Determining the actual mechanism of myocardial injury.
  • Further studies are required out-with a fire training facility to assess the effects of real-life fire suppression which will encompass the additional triggers of psychological stress and air pollution.
  • Further experimental studies would be required to be undertaken to explore the effects of each of the components of (i) heat and (ii) exercise on cardiovascular function, separately.

However there are key lessons which need to be addressed through measures implemented as quickly as possible.

The report highlights the importance of one simple measure such as staying well-hydrated which will contribute to reducing the risk of heart attacks. No doubt this will be seized upon by some so-called “fire service leads” as the solution to the problems highlighted in the BHF study. Whilst hydration is an essential step long-advocated and supported by the Fire Brigades Union it is not new and in large part due to the efforts of our health and safety representatives has been addressed across the UK through the provision of bottled drinking water on front-line appliances. As a consequence re-hydration is not new and is well-practised. Our safety reps will ensure that water-provision policies and practices are reviewed to ensure that they are robust in the light of this new report.

Being well-hydrated is merely a means to address the symptoms caused by more fundamental problems which are neither newly-identified nor in the gift of firefighters to resolve.

The key issue is that of taking measures to reduce the length of time that firefighters are exposed to heat and exertion at incidents. The report states, with our emphasis added:

“Our study has important implications for firefighters participating in fire simulation training. If the increased thrombogenicity and impaired vascular function observed in our study is secondary to an increase in core body temperature dehydration then limiting the duration of exposure, active cooling and effective rehydration would be sent and inexpensive ways to mitigate the risk posed by fire simulation training.”


Members across the country need no reminding of the death of Brother Tom Naples in Northumberland whilst attending a breathing apparatus training event. Similarly many members have been subject to heat burns and heat stress at BA/fire behaviour training sessions including hospitalisation. In East Sussex a member nearly died in similar circumstances.

These are events which have taken place in controlled environments. On too many occasions under-resourcing has been a clear contributory factor in the deaths of our members at fires. Poor planning and defective incident-resource policy at principal management level; weak scrutiny and understanding at fire authority level; pitiful lobbying for improved funding at sector level; and disinterest at governmental level have all contributed to insufficient capacity being available on the incident ground. This insufficiency is manifested in reduced crewing levels on pumping appliances; inadequate pre-determined attendances (PDAs); the introduction of pointless small vehicles with 2 or 3 riders and closures of stations and reduction in the number of pumps.

The effect of the above has resulted in crews having to enter fires at a later stage than in previous years such that the fires are more developed with greater exertion being demanded of, and delivered by, firefighters.

Whilst a matter of disgust, it is of little surprise therefore that a common factor at incidents where firefighters have died has been too few firefighters available to incident commanders and multiple breathing apparatus wears by the same crews when one wear should be the maximum.

It is of note that the report brings attention to an important issue regarding firefighters’ awareness of their physiological condition which reinforces the demand for single-wear practice:

“Ratings of perceived exertion are commonly used in simulated real fire exercises. However, there is generally poor correlation between perceived exertion and heart rate with most subjects grading exercises as less strenuous than their heart rates would otherwise suggest. This raises an important safety issue and questions if firefighters are aware they are working at the limits of their physiological capabilities.”

Operational guidance for breathing apparatus is woefully inadequate following the abandonment of its mandatory status and looser wording when released in January 2014. Similarly, we have fire and rescue services embedding bad practice and unsafe thinking. Examples of this are FRSs misapplying dynamic risk assessment and operational discretion suggesting that all operational policy is for information rather than observance; and consciously leaving station-based managers in situations where they have inadequate personnel to deal with an incident whilst knowing the drive of the operational imperative.


The Fire Brigades Union will consider the report in depth and will use it as part of our continuous campaigning, lobbying and awareness-raising.

All members are urged to maintain and improve the current practice of ensuring they are hydrated. By doing so members will take what steps they can to reduce the risk of heart attack however the biggest challenges are those for whole Union:

  1. to ensure that the report isn’t miss-used to create a false narrative that suggests that the solution to reducing the exposure factor lies in the hands of firefighters; and
  2. to campaign for the resources for the incident ground to minimize the exposure to extreme heat and over-exertion which, along with psychological pressures, are the principal causes for physiological processes which give rise to the risk of death for firefighters from cardiovascular events.

Best wishes.

Yours fraternally


Assistant General Secretary


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