It is well known and globally documented that heat exposure from fires can have a detrimental effect on firefighter’s health. The Fire Brigades Union (FBU) and the National Fire Chiefs Council (NFCC) have both provided guidance and training on the effects of over-exposure and the prevention of heat-related illness. Until recently, however, there has been no substantial research in the UK into the possible side effects of long-term repeated exposure to extreme heat, as commonly experienced by instructors.

In 2016, the NFCC published its Health Management of Compartment Fire Behaviour Instructors (CFBIs) document that provided detailed guidance on risks and recommendations for best practice within the training environment. The document is thorough, but it raises concerns about the need for further research here in the UK: ‘One possible side effect of repeated exposure to an extreme thermal environment is an unfavourable change in the immune system. Richardson, Maxwell, Watt, Smeeton and Wilmott in their research Heat Exposure and the Immune Function in Fire and Rescue Service Personnel (2013) point to the fact that while previous studies indicate short term changes in immune function, there is currently no research into longer term health risks associated with the severe repeated exposures particular to CFBIs’.

Within its recommendations the document states: ‘Further research to be undertaken to establish a scientifically based safe exposure frequency which enables effective acclimatisation together with sufficient rest and recovery time to ensure the health and wellbeing of individuals’.

At the time this document was published, the NFCC was already aware of some preliminary research into the health of instructors taking place in Southeast England. Dr Alan Richardson, a lecturer in Exercise and Environmental Physiology at the University of Brighton, had been approached by the South East Fire Instructor Welfare Group who were concerned about their health, and an initial research project involving a small group of instructors has since spiralled into a much larger and in-depth project that is currently in its final stages of review.

Research Overview

The Physiological, Immunological and Contaminant Monitoring of Firefighters and Instructors is a project that started in 2018 and is funded by the Fire Service Research and Training Trust because too many questions and concerns have been arising around long-term firefighter health. The report states: ‘Previous [research] has not investigated in combination the physiological stress, immune suppression, inflammation and contamination of Fire Service personnel over acute or long-term exposure. Nor has it considered the issue of exposure amounts or fire types in simulated or real fires. This proposal aims to consider these issues in a large UK firefighter and fire instructor population to show the acute and chronic impact of fire exposure on health, which builds on this group’s body of Fire Service research’.

Data was gathered over a six-month period with the intention of measuring inflammation, contaminants and psychological factors from a group of 99 firefighters, 45 instructors and a small control group, in response to their exposure volumes and type. The methods included collecting blood and urine samples for analysis, measuring heart rate and core temperature during live fire operations and questionnaires evaluating mood and mental wellbeing.

The key findings on how heat exposure effects inflammatory markers and immune system function demonstrate that there is a severe inflammatory response in some fire instructors, which is likely to be the result of severe over-exposure to extreme heat and activity. Immediately following an acute exposure, instructors typically feel worse than firefighters: they feel hotter, more confused, more fatigued and experience more muscle pain. After an exposure, core temperature continues to rise for 10-15min and it typically takes a minimum of 60-80min for core temperature to reduce back to within resting levels, although in some cases it takes longer. Overall, instructors exhibit chronic systemic inflammation, which is associated with exposure number and does not appear to be affected by age, BMI, systolic and diastolic blood pressure or mood state. This demonstrates and supports the need for Fire Service policies on maximum wear numbers to be introduced in the UK and internationally.

Unfortunately, the contaminants research has been delayed due to Covid-19, and the samples are still under analysis. This research differs from the UCLan contaminants project because the methods used involve the analysis of urine samples at baseline and after logged fire exposures, whereas the UCLan study analysed contamination found externally on skin and PPE, therefore the results are eagerly anticipated.

Professional Opinion

Lead researcher, Dr Alan Richardson, and colleague Dr Emily Watkins, a lecturer in Exercise and Environmental Physiology at the University of Roehampton, spoke to FIRE about the key findings and recommendations that have come from the research so far.

Dr Watkins has been a key figure in collecting the data, analysing the results and writing up the concluding paper. She found that firefighters tended to have normal levels of inflammatory markers, but instructors, who are exposed to more fires, showed different results. Dr Watkins says: “Going into more than 15 fires a month shows elevated levels of numerous inflammatory markers, and there was an indication of immune suppression going on there as well. All of these things together are suggesting that if you are an instructor and you are exposed to a large number of fires a month, you are possibly at risk of impacting your immune system and you may be putting yourself at higher risk of a cardiovascular event in the future. That’s not to say that fire instructors should stop doing their job, essentially we need to think about the working practices they use and how can they reduce those risks.

Minimising the physiological strain they experience from each individual fire is important. What we think is happening is that they are experiencing an exposure, the inflammatory levels go up because the physiological strain goes up – and that’s a perfectly normal response – but they haven’t got that recovery time before they are putting another fire on top of it, and so the levels are progressively increasing. It might be helpful to minimise the original strain from each fire.”

Dr Watkins’ acute recommendations include: “Simple things like making sure they are hydrated before going into a fire, possibly using pre- and post-cooling mechanisms – drinking an ice slurry for instance – can also help. If they start experiencing the classic symptoms of over exposure – extreme fatigue, mood swings, sweating at night or broken sleep, or heavy sweating for no other physical reason, heart palpitations, headaches – then it might be a case of looking at the staffing, look at the rota: is enough being done for that individual? Can their working patterns be altered slightly, or can their exposures be reduced for a little while to enable them to recover?”

Once any acute interventions have been put in place, it is time to think about introducing a maximum number of exposures per month. Dr Watkins continues: “If they’re doing between nine and 15 they would be in the reasonable or lower end, but we’ve seen some instructors doing up to 40 exposures a month, which is drastically higher.

“Health problems in the long-term, if not monitored and dealt with, result in more days off sick due to an increase in illnesses because of a reduced immune system, and ultimately, people leaving the job itself because of burnout. Essentially it’s about ensuring that instructors that want to be instructors can stay in the role for as long as they can, because they have an incredible amount of experience and knowledge, and while carrying out our research it’s been honestly astounding to witness their skills.”

Dr Richardson has been researching firefighter health for eight years and has written numerous papers on the subject. His main concern throughout this project has been the welfare of instructors: “The initial research looked at just six instructors and noted that they all had really high inflammatory markers and showed real immune suppression. We needed to do more work on a larger group to get better results. [Instructors] are exposed to fire, heat and smoke much more than firefighters. The training courses are notoriously hard work, as most firefighters will tell you, but imagine how it is for the instructors who have to repeat these exercises over and over.

There has previously been guidance in place that recommended a maximum of one exposure a day, three a week and nine a month, and that seemed like a really good idea at the time, but obviously with funding and efficiency cuts that hasn’t always transpired. There are many places that are subjecting their instructors to much more than that.”

The instructors in this research project have all reported similar health issues, including night sweats, sweating black soot, struggling with thermal regulation, mood swings and muscle cramps, which are indicators of developing health issues. Dr Richardson says: “It’s a real challenge. You can’t expect people to do this long-term and be ok with it. What we have found is that if you suffer with long-term inflammation and immune suppression, it’s not going to be helping your health, that’s for sure. We need to manage the workloads of instructors effectively. We really need to reduce the exposures to around ten or less a month. I realise money is a factor these days; I just think we need more instructors that can be firefighters as well, so we can spread the workload of teaching.”

Physiological monitoring during a wear has proved to be the biggest challenge in gathering data. Being able to accurately monitor core temperature in real time would allow those who are getting too hot to be pulled out before temperature becomes critical. Dr Richardson says: “The problem right now is that there doesn’t seem to be good enough technology that’s cheap enough to run efficiently… there’s no feasible way of measuring someone’s physiological response to the environment during training or real-life fire scenarios. There’s nothing right now that is of reasonable accuracy, quick enough to put on, or easy enough to set up with Bluetooth or Wi-Fi or a local area network; it’s too hot for anything with a battery and you can’t have a mobile phone on you. There just isn’t a product that’s suitable right now.”

Dr Richardson thinks this technology would work well for new recruits: “When they first experience the training, they don’t know their limits. They might be a bit anxious and they might push too hard to pass the tests. This technology would indicate when their bodies have had enough before the symptoms of heat illness set in; you could immediately see if someone is getting too hot and pull them out.”

Going forward, Dr Richardson would like to see the recommendations below implemented throughout the service: “We now need to influence policy rather than doing any more research. When the operational policies come to be written again, hopefully we can link in and write the guidance on the subject.”

Further recommendations and considerations from the concluding research report:

  • Development of a physiological monitoring device is needed, with an implementation plan produced for effective use
  • Physiological monitoring of BAI and particularly new recruits during training wears is warranted
  • BAI exposures should ideally be kept to the no more than nine a month, but certainly should not exceed 20.
  • Training centres should ensure adequate advice and facilities regarding hydration and cooling methods. Ice slurries are recommended as a beneficial and logistically useable cooling intervention.

‘[Instructors] should receive more frequent and comprehensive medical checks than [firefighters]. These could include monitoring the classic [instructor] ill health symptoms, exposure numbers and screening for common cancers. Regular checks should be used to identify changes in health over time, so workloads can be adjust as required’.