Fire Fighting Heat Stress During Wildfires

Fire Fighting Heat Stress During Wildfires

Firefighters protect people, places and the environment, but how do fire services protect their crews amid global warming and rising wildfires?

A changing climate requires fast response

Heat-related illnesses are a disturbing reality for firefighters everywhere

Nearly half of firefighters who died, do so from cardiovascular events linked to heat-related illnesses

Overcoming HRI challenges this wildfire season


A changing climate requires fast response

As many parts of the world endure another season of wildfires, firefighters are bracing themselves for more unnerving events that not only affect the environment, but the people living there. “Wildfires and heat stress are commonly occurring natural hazards that lead to loss of lives and livelihoods and which are increasingly impacting upon our society”. It’s reported that, globally, at least 330,000 deaths are linked to wildlife pollution, highlighting  the severity of the impact wildfires have on our planet.

There is an observed global and regional impact on ecosystems and human systems attributed to climate change in IPCC’s latest report. Findings show the global impact on health and wellbeing for ‘heat, malnutrition and other’ is reaching the ‘high or very high’ category and increasing, further showing the dire situation we face when it comes to rising global temperatures. While world leaders work to reverse the rising temperature of our climate, it’s vital we look at the impact on those who risk their lives to protect us, our homes and our environment – our firefighters.

In 2021, reports unveiled the harrowing effects of wildfires on firefighters on the frontline. A volunteer firefighter in Greece, who had given up his free time to help save lives, died after suffering severe burns when the vehicle he was in caught fire. In Bolivia, firefighters have been so dehydrated they suffered severe headaches for two days afterwards. Cases like this are far too common with the concerns of firefighters escalating as temperatures continue to intensify year on year. 

Globally, firefighters are suffering the impact of extreme heat. A study in New South Wales, Australia, found that more than 75% of firefighters experience heat-related illnesses (HRI) such as headaches, sudden muscle cramps, dizziness, nausea, and fainting.

A separate study in Korea revealed almost identical numbers with  74.8% of firefighters experiencing at least one HRI throughout their career in their line of duty. This study also demonstrated that long shifts, as well as PPE worn during rest, correlated with the occurrence and frequency of HRI symptoms. Similarly, CDC reported that firefighters can address heat stress by reducing the physical workload per individual and encouraging more frequent and longer breaks to allow firefighters to dissipate their excess internal heat.

Firefighters are encouraged to remove their helmets and gloves upon rest when it’s safe to do so to limit the risk of HRI. PPE inhibits the evaporation of sweat, preventing sufficient cooling of a person’s core body temperature (CBT). Critically, this research signifies the need for fire and rescue services to implement more effective strategies to protect firefighters against HRI – beyond requesting firefighters to intermittently remove heat-trapping PPE and reduce their hours on call.

Another method of protection against HRI for firefighters at work is, of course, hydration. The Fire Brigades Union (FBU) in the UK highlights the requirement for firefighters to hydrate a third more than the standard person:

“On a standard day, the human body can expect to lose two litres of water through sweat. 45 minutes of exposure to extreme heat can lose a further litre for a firefighter. When rehydrating, it’s important to replace 150% [of] what has been lost – so that’s 1.5 litres for each 45 minute exposure.” 

Hydrating, removing PPE at rest and reducing hours of heat exposure are, undeniably, life-saving guidelines for firefighters at work. However, statistics indicate these actions aren’t enough to protect firefighters from the effects of blazing heat in the face of a rapidly changing climate.

It’s clear that firefighters are routinely exposed to extreme temperatures, which can quickly lead to HRI. Routine exposure to extreme heat can also have severe long term implications that can lead to cardiac failure as the body struggles to adapt to the challenging environment, usually compounded by dehydration and PPE-wear. The link between heat stress and cardiac death is a growing concern, with similar statistics appearing around the world. Cardiac death accounts for almost 50% of all firefighter duty-related fatalities in New South Wales. Similarly, in the US, research suggests that 45% of on-duty firefighters died due to cardiovascular events.

Research from the University of Edinburgh supported these findings, showing “a direct link between the heat and physical activity levels encountered by firefighters during the course of their duties and their risk of suffering a heart attack”. A firefighter in the UK was close to death following a heart attack, possibly caused by the thickening of his blood due to dehydration from the extreme temperatures he’d been working in.

When firefighters (or anyone) suffer from heat stress and dehydration, their CBT is elevated. The process of increasing blood flow to the skin to enable cooling and regulate CBT, also known as thermoregulation, is taxing on the cardiovascular system as the heart needs to pump harder and faster, especially when blood volume is reduced due to dehydration. While humans develop improved mechanisms of thermoregulation over time through acclimatization, the risk of cardiac injury is high for firefighters exposed to heat of this level. In addition, newly recruited firefighters have an even greater risk of cardiac injury, having not been exposed to such temperatures previously. Similarly, as we age, the body becomes less effective at thermoregulation and therefore older firefighters will naturally have a higher risk profile of heat stress.

However, heat stress can be effectively managed through access to specific physiology data  of the individuals at work as opposed to measuring the environments in which they’re working. This is where the industry requires technology to save the lives of firefighters on the frontline, especially during wildfire season.

Bodytrak Device

The Bodytrak Device consists of a comfortable, easy to wear Earpiece and communications pack (CommPack), which can conveniently clip to a belt or be placed in a pocket. The device provides 8 – 12 hours of use, audible alerts and data transmission to the cloud.

Overcoming HRI challenges this wildfire season

With the global annual average temperatures rising over the last 150 years and extreme weather events increasing rapidly, fire services require new PPE solutions for firefighters to safely tackle bigger blazes. Wearable technology adds considerable insight into the health, safety and welfare of users exposed to the harshest conditions created by wildfires. Despite consumer wearable technology advancements in recent years, fire departments require fit-for-purpose ruggedised solutions for active monitoring of multiple risk factors. This includes heat stress/stroke, fatigue, dehydration, hyper/hypothermia, psychological stress, endurance, concussion impact and fitness for deployment, all in real-time, accurately and across multiple easily identifiable users.

Despite wrist-worn devices adequately measuring heart rate in laboratory-based activities (Shcherbina et al., 2017), their inability to provide a reliable reference of CBT, even with the use of algorithms, is a distinct limiting factor for the use of this technology for the monitoring of heat stress. Meanwhile, the same could be said for chest-worn devices or smart clothing which all measure via the skin, with no natural orifices in the chest, arm or leg regions. When monitoring CBT, the deeper into the skin the better as this makes the accuracy higher, reduces false positive alerts and allows fire and rescue services to effectively monitor their crews.

Bodytrak Earpiece

Due to its proximity to the hypothalamus (the temperature control centre of the body), the ear is an excellent site to measure core body temperature and heart rate. As a result, Bodytrak is extremely effective and accurate. The Earpiece is also designed to fit comfortably under existing personal protective equipment (PPE).


Bodytrak is fuelled by data science with a solution that’s designed to safeguard workers including firefighters from incidents caused by heat stress, fatigue and more. The physiological responses captured are analyzed simultaneously to provide alerts to the user and supervisors if thresholds are exceeded in order to provide rapid intervention and support.

Alongside real-time monitoring, important features such as geolocation, geofencing and SOS alert add another level to safeguard fire crews. Whenever an alert is generated, Bodytrak can instantly identify where the firefighter is located whether they are indoors or outdoors, allowing rapid assistance to be deployed. To supplement the indoor and outdoor geolocation, precise indoor vertical positioning is also available within the same solution, which can be critical during emergency evacuation when every second counts. Similarly, the SOS alert is a simple user-activated alarm that is triggered on the dashboard and via SMS and email when urgent support is required. For fire fighters who are often entering unknown conditions to battle extreme blazes, these life saving measures act as a new type of buddy system should they face a man down situation.

Bodytrak has the power to keep fire services across the globe running safely each wildfire season and throughout the year. Our solution ensures entire workforces are safe while maintaining productivity and avoiding burnout. Bodytrak is the only non-invasive solution of its kind on the market, driven by data to give your firefighters the peace of mind to get the job done and return home safely at the end of their shift.

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