Firefighters rely on their protective equipment to stay safe in dangerous conditions. To help ensure that new firefighter gear meets safety and performance standards, Dr. Caroline Smith from Appalachian State University is studying how these updated materials affect the body’s ability to cool itself during extreme heat.
Smith is a co-principal investigator on a project led by Dr. R. Bryan Ormond of North Carolina State University, funded with $1.5 million from the Federal Emergency Management Agency’s Fire Prevention and Safety Grant Program. The research teams are examining how firefighters’ bodies respond to new moisture barriers in turnout gear, which are designed to reduce contact with harmful liquids and bloodborne pathogens.
These new barriers do not contain polytetrafluoroethylene, a chemical known as a “forever chemical” due to its persistence in the environment and potential health risks such as increased cancer rates among firefighters. Some manufacturers have already updated their products to comply with new standards and state bans on these chemicals.
However, there is limited real-world data about how these new layers affect heat release and moisture management for firefighters working under extreme conditions. Smith explained, “With changes to the moisture barrier potentially altering the thermal management, firefighters may potentially be under more thermal and cardiovascular strain. In short, if they are hotter, their hearts end up working harder.” She added, “So if these guys get hotter and they’re under strain, that’s a problem and they need to be aware of that.”
Cardiac events account for 45% of firefighter fatalities each year according to the Centers for Disease Control and Prevention. The study will examine whether the updated gear increases core body temperature, heart rate or dehydration—factors that can raise the risk of heat stroke or cardiac incidents.
Over several months, six Boone-area firefighters and 12 from Raleigh will participate as volunteer test subjects in field tests and controlled lab environments at Appalachian State University’s Beaver College of Health Sciences. They will perform tasks such as swinging hammers, dragging hoses, and climbing while wearing different types of gear so researchers can monitor physiological responses.
As part of testing protocols, participants swallow telemetry pills that transmit real-time core body temperature data via radio signals. Researchers also measure heart rate, skin temperature, sweat loss, gas exchange (oxygen use versus carbon dioxide production), metabolic rate calculations, and cognitive functioning during heat exposure.
Smith noted: “If you get very hot and if you’re at risk of heat illness, your cognitive function can change, and that can be dangerous if your decision-making changes in an emergency situation.”
Her broader research focuses on routes through which carcinogens enter the body—especially through skin absorption—in occupational settings like firefighting. Smith has used techniques such as placing catheters under the skin or intradermal microdialysis paired with laser Doppler flowmetry to track contaminant exposure levels over time and assess effects on skin blood flow or thermoregulation.
She said understanding where contaminants are absorbed could help improve decontamination procedures: “The overall goal for this project is to improve firefighter health and safety.”
Appalachian State University offers academic programs across campuses totaling 1,200 acres designed for various uses including academics and recreation (https://www.appstate.edu). The university serves more than 21,000 students through undergraduate and graduate offerings (https://www.appstate.edu) at locations in Boone and Hickory as well as online programs reaching students beyond its physical campuses (https://www.appstate.edu). App State is recognized nationally for its value and innovation by outlets like U.S. News & World Report (https://www.appstate.edu), belongs to the University of North Carolina System (https://www.appstate.edu), aims to prepare engaged global citizens focused on sustainability (https://www.appstate.edu), and maintains a low student-to-faculty ratio with over 150 undergraduate majors available (https://www.appstate.edu).
