Note: This article originally appeared in the June 2024 Issue of International Fire Fighter magazine, page 60.

In the realm of firefighting, every innovation in protective gear holds the potential to save lives. With the advent of modern building materials contributing to fires that burn hotter and faster, the risks faced by emergency responders have escalated. Now, more than ever, ensuring firefighter performance, comfort, and safety is paramount.

In response to this critical issue, Fire-Dex, a leader in firefighter protective apparel, has introduced new turnout gear that empowers everyday heroes to confront challenges with greater resilience and return home safely after their mission.

At the heart of this innovation lies groundbreaking ventilation technology, enabling wearers to regulate their core body temperature more effectively. Unlike the industry’s previous attempts at ventilation, this dynamic system operates as a one-way street, promoting airflow to facilitate sweat evaporation without compromising the gear’s protective function, thereby addressing the risk of heat-stress-related incidents, the number one cause of line-of-duty deaths for firefighters.

Turning Up the Heat

Modern construction materials such as plastics, foams, and composites often incorporate synthetic components that are more flammable than traditional materials like wood or masonry. These tend to burn hotter and faster, releasing toxic gases and producing intense heat. Additionally, building design has evolved to prioritize factors like energy efficiency and cost effectiveness. As a result, structures are often built with open floor plans and larger windows, which can contribute to rapid fire spread and increased intensity.

By prioritizing heat and moisture management alongside traditional protective features, manufacturers like Fire-Dex are revolutionizing turnout gear design, ultimately safeguarding those who bravely serve on the front lines where the ability to effectively manage heat and moisture can mean the difference between life and death.

The Science Behind Sweat

This is where Resistance to Evaporative Transfer (Ret) emerges as a critical metric for evaluating turnout gear, alongside more familiar metrics like Total Heal Loss (THL) and Thermal Protective Performance (TPP). Ret testing assesses how well a garment facilitates the evaporation of sweat, thereby influencing the body’s cooling efficiency. Notably, athletic clothing and accessory companies have also adopted Ret testing in their product development processes, allowing them to engineer apparel that optimizes sweat evaporation.

When the body is subjected to heat, it responds by sweating. Sweat, when it evaporates from the skin’s surface, carries away heat, thus cooling the body. This process is vital for maintaining thermal equilibrium and preventing heat-related illnesses.

However, when firefighters don layers of clothing designed to shield them from external heat sources, this natural cooling mechanism is hindered. Turnout gear is engineered to block radiant, convective, and conductive heat transfer, thus impeding the body’s cooling process and emphasizing the necessity for sweat to have a proper exit route.

According to NFPA statistics for Firefighter Deaths by Cause of Injury in 2022, a staggering 51% of LODDs are attributed to overexertion/heat stress, underscoring the urgent need for innovative protective gear designed to effectively mitigate heat stress.

Cooling to the Core

Turnout gear has traditionally focused on providing robust protection against external hazards, often at the expense of breathability and heat management. However, advancements in material science and garment engineering have paved the way for vented ensembles that strike a balance between protection and comfort. Achieving effective venting in turnout gear is no small feat. It requires meticulous consideration to ensure that airflow is optimized without compromising protective properties. One of the key challenges lies in maintaining the gear’s overall moisture and heat integrity while allowing for airflow.

“The industry has attempted vented thermal liners or outer shells, but achieving simultaneous moisture barrier ventilation has been a major challenge,” explains Todd Herring, Fire-Dex’s Vice President of Product Innovation and Strategy. “The problem lies in creating a system that allows air to flow out for cooling while preventing external elements from infiltrating.

“Fire-Dex has pushed the boundaries of turnout gear design by integrating its proprietary AeroVent™ Technology into their new AeroFlex™ suit. This approach involves creating a one-way airflow path that expels heat and moisture from within the garment and prevents liquid and contaminant ingress at the same time—accomplished through a combination of advanced materials, strategic vent placement and exclusive construction techniques.

“With AeroFlex™, we create a microclimate within the gear that consistently maintains a pressure differential to the outside environment, so it can breathe while creating an effective barrier against water, heat and impurities. Venting through all layers of the thermal liner and moisture barrier is the key to performance and something that hasn’t been achieved until now.”

Technically Brilliant Protection

Within the AeroFlex™ suit is a breathable VaporLite™ Panel three-layer composite system, strategically placed in areas of the body prone to heat accumulation—the inner thighs, armpits, side seams, and behind the knees. The vents enhance cooling precisely where it’s needed most, allowing sweat to evaporate more efficiently than any garment available to the fire services today. As a result, firefighters are able to experience rapid cooling upon exiting a high-temperature environment and thereby improving their post-exertion rehab.

“By promoting airflow through dynamic movement, the technology generates a constant cooling sensation,” says Herring. “As the wearer becomes more active, increased air circulation within the garment results in a heightened cooling experience. The fabric is also working to draw sweat away from the skin to aid evaporation through rapid wicking, so the body can better self-regulate.”

Together, these patent-pending technologies from Fire-Dex deliver Resistance to Evaporative Heat Loss (Ret) values as low as 15 and Total Heat Loss (THL) performance as high as 348, as demonstrated in a composite performance review inclusive of leading competitor panels.

Moreover, Fire-Dex’s commitment to firefighter safety extends beyond heat dissipation. AeroFlex™ turnout gear further integrates particulate-blocking technology into the vents, acting as a barrier against potentially harmful carcinogens. Additionally, the turnout gear incorporates optimized shoulder seams, knee panels, and leg openings to align with the body’s natural hinge points, creating minimal coat rise, enhanced flexibility, and greater ease of donning and doffing boots.

Cooler, Safer Gear

As firefighters gear up, they’re not just preparing for battle against flames; they’re equipping themselves with a shield against exertion and unseen dangers. With AeroFlex™ leading the charge, Fire-Dex is seeking not only to redefine comfort in the line of duty but has also crafted a defense against the silent threats that linger in the aftermath of every blaze.

As the leading cause of LODDs, heat stress demands proactive measures, and confronting the challenge requires a strong commitment to serving those who serve. For Fire-Dex, it’s about introducing a new era in comfort, safety, and resilience, ensuring that everyday heroes return home safely after every call.