The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to improve occupational safety and health outcomes within the fire service through translational research and development of an affordable wearable physiologic monitoring device. Nearly 50% of firefighter line of duty deaths are the result of sudden cardiovascular events and the societal costs of firefighter injuries are in the billions of dollars, yet many departments cannot afford the costs of implementing the firefighter monitoring programs. Therefore, the use of an affordable wearable which can gather, store and transmit physiological data in real-time has the potential to reduce fatalities, injuries and costs. The affordability of manufacturing the device is the major commercial innovation as it will extend the physiological monitoring capability to workers exposed to extreme environmental conditions such as firefighters, soldiers, chemical and biological lab technicians, and commercial drivers - groups that have not been able to afford the cost of longitudinal and/or real-time physiological monitoring and predictive diagnostics. The affordability of the device will enable researchers to further scientific knowledge correlating the interrelationship between experimental physiological monitoring and field-based data. The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to improve occupational safety and health outcomes within the fire service through translational research and development of an affordable wearable physiologic monitoring device. Nearly 50% of firefighter line of duty deaths are the result of sudden cardiovascular events and the societal costs of firefighter injuries are in the billions of dollars, yet many departments cannot afford the costs of implementing the firefighter monitoring programs. Therefore, the use of an affordable wearable which can gather, store and transmit physiological data in real-time has the potential to reduce fatalities, injuries and costs. The affordability of manufacturing the device is the major commercial innovation as it will extend the physiological monitoring capability to workers exposed to extreme environmental conditions such as firefighters, soldiers, chemical and biological lab technicians, and commercial drivers - groups that have not been able to afford the cost of longitudinal and/or real-time physiological monitoring and predictive diagnostics. The affordability of the device will enable researchers to further scientific knowledge correlating the interrelationship between experimental physiological monitoring and field-based data.