Fire departments tackle heart rate increases with new alarm approach

Jarring alarms may be part of the culture of firehouses, but officials in Danbury, Connecticut, say they also can hit firefighters’ bodies at the moment they need to stay calm. The Danbury Fire Department began using a new dispatch system in September that starts with softer tones and relies on a computerized voice to relay information about incoming emergencies, with warm lighting and monitors at stations providing details as crews prepare to respond.

The department’s former alert setup, according to Capt. Kevin Lunnie, delivered alarms and tones at high volume right away. Lunnie said the effect could be “overwhelming,” and he noticed a jump in his heart rate when alerts went off—an issue he raised in the context of a broader health risk for firefighters. Heart problems are the leading cause of on-duty deaths in the profession, the report noted.

Under the newer approach, Danbury’s alerts ramp up rather than arriving at full blast. Lunnie said, “It’s much easier on your nervous system.” In one example described from a Danbury fire station, an incoming call begins with a single, soft tone and an automated voice identifies the unit and what crews are responding to, including the patient address, while station monitors display the emergency’s nature and location and a countdown timer begins.

Danbury’s update is designed to make alerts both calmer and clearer than earlier systems, the report said. The older setup started with full-volume single tones followed by longer alerts that fluctuated between high and low pitches, and dispatchers previously announced calls over a station speaker system that firefighters described as static-y and hard to understand. “Most people found it very jarring,” Lunnie said, describing how the earlier system could jolt firefighters awake day or night.

Officials also linked the station alert changes to dispatching speed and workflow. The new setup runs within the computer-aided dispatching system so that when dispatchers take an emergency call and log initial information, it can alert stations and units faster than before. The system also sends call information to firefighters’ phones and watches, Danbury Assistant Fire Chief William Lounsbury said, and he attributed quicker response times to that integration.

Danbury paid for the Phoenix G2 system with federal pandemic-relief funds, according to the report. The city tapped around $500,000 from the 2021 American Rescue Plan Act to cover the installation of the Phoenix G2 dispatch technology, built by Honeywell subsidiary US Digital Designs. Honeywell said that the same Phoenix G2 system is in nearly 6,000 firehouses in the United States, and other companies make similar alerting systems used in stations nationwide.

Supporters of progressive-volume alerting point to research aimed at physiological stress, including a study from Beloit, Wisconsin. The report said a decade-old study found that alert systems using an immediately loud sound increased firefighters’ heart rates by a median of seven beats a minute, compared with five beats a minute under a system that phased in volume; researchers described the difference as statistically significant even if the gap was relatively small.

In the study’s author cohort, Dr. Jay MacNeal—associate emergency medical services director for the Beloit Fire Department—said in an interview included in the report that ramp-up alarms kept heart rates lower to the alarm. “When the alarm was used in a ramp-up fashion — so a gradual buildup on the alarm — the heart rate was lower to the alarm, so it put less stress on their body,” MacNeal said. The study included more than 40 Beloit firefighters and was published in the Journal of Occupational and Environmental Hygiene in 2016 by researchers from the Mercyhealth Emergency Medicine Department in Janesville, Wisconsin, and Yale University.

The report also pointed to public safety data and shifting standards. The National Fire Protection Association said that of the 51 on-duty firefighter deaths in the U.S. in 2024, 20 were caused by sudden cardiac death, the leading cause of fatalities. Last year, the NFPA issued new standards for fire station alerts that call for alarms and tones starting at lower volumes and using calm, computerized voices to reduce stress. The International Association of Fire Fighters, a union representing more than 360,000 firefighters and paramedics in the U.S. and Canada, supports progressive-volume alerting but is seeking specific standards for design details.

Sean DeCrane, the IAFF’s assistant to the general president for health and safety, said research on the best way to alert firefighters remains limited and that systems now on the market differ. “We would like to see an industry standard that really starts to define the decibel levels, the intervals, the integration of turning on the lights, what that progression should be, and we believe the standard should be based on research,” DeCrane said.