INVISIBLE DANGER: Firefighters' hearts at risk

For Matt Frantz, the sound of the pager going off in the middle of the night sent his heart racing. He was the Chief of the fire department in Rice Lake, Wis.

"He'd be boom, like a sling shot throwing on his pants and throwing on his shirt," said Matt’s wife, Jennifer. "I'm like, ‘Okay, be careful’ and he'd already be flying out the door," 

One of those calls was a chimney fire at 1:00 a.m. in December of 2013. It was canceled and he returned home. After a few hours of sleep, he went to his full-time job as a UPS delivery driver. 

When Jennifer got home from work a sheriff's deputy met her.

"The deputy looked at me and said, 'I'm sorry ma’am, he's gone,'" she said. "I'll never forget it. It's clear as day, three years later.”

Matt Frantz died from a heart attack. He was 42. 

It's a little-known fact that this is how most firefighters die in the United States. 

Shane Clifton, a St. Paul firefighter and paramedic, was only 38 when he died of a massive heart attack while on duty at fire station No. 14. Help was right there--but it wasn't enough. 

Nearly half of all firefighters will die on duty, not from smoke and flames but from cardiovascular disease. 

Others, like Matt Frantz, will die hours after coming home from a fire. His is still considered a “line of duty death” under the Hometown Heroes’ Act, which covers any public safety officer who has a heart attack within 24 hours of being on duty.
"He didn't die fighting a fire, but it didn't matter. He got up at midnight, 1:00 to help fight a fire,” Jennifer said.

Matt was ahead of the curve. He'd lost 65 pounds in the last few years and was trying to get his volunteer department healthier. 

In his absence, Jennifer longs to hear once more the very sound that would send his heart racing. 

"Not that you ever really want to have a pager," she said. But yeah, I miss that, still. And I'm proud of him for getting up in the middle of the night. The pager was a badge of honor for him."


Dr. Zeke McKinney specializes in occupational medicine at HealthPartners. He said the demands on firefighters' hearts are enormous. 

"Heart disease generally makes up to 50 percent of deaths in firefighters," he said. "That is fairly contemporary data."

McKinney compares the demands on firefighters to that of a sprinter.

"They go from being sedentary at their desk, awaiting a fire call and suddenly they get the alarm, their heart races and off they go," McKinney explained.


The Fox 9 Investigators wanted to know just what that alarm does to a heart rate. So, as an informal experiment, the Richfield Fire Department agreed to wire up their firefighters with heart rate monitors. Assistant Chief Mike Dobesh coordinated it.

"This firefighter had a base line heart rate of 62 beats per minute, their heart rate was elevated to 131 beats per minutes, which obviously more than doubles their heart rate, just based on that alarm response,” Dobesh said.

Over six days of monitoring, that was the pattern. The heart rate doubled when the calls came in and remained high for three to 11 minutes after the initial spike.

"When your heart races so acutely, your body releases hormones that really stimulate your heart rate and that additional stress so suddenly could trigger some heart disease," McKinney said.

And keep in mind, that's before they ever get to the fire.


Once there, they'll be exposed to carbon monoxide and hydrogen cyanide, two chemicals that suck oxygen out of the blood.

And while their breathing apparatus will filter out most chemicals, many firefighters take off their masks too quickly when the fire is out.

"During that time the noxious or toxic gas exposure is still there," McKinney said.

There's also the enormous physical and psychological stress of battling the fire, not to mention the intense heat. 


A British study looked at how heat affects healthy firefighters in a simulation. Researchers found there's an increase in the formation of platelets in the blood--leading to blood clots and a chemical disruption in the lining of the vascular wall, cutting off the blood supply.

Even in an otherwise healthy person, that is a recipe for a heart attack. 

The study was published in the journal Circulation in April.


Richfield Fire is among those departments putting an increasing emphasis on physical fitness. 

Seconds before a call comes in, a red light goes off, giving the body a kind of advance warning of what's to come, instead of a jarring alarm--or a pager--in the middle of the night.

Brian Wienholz also served as a volunteer firefighter before working full time at the Richfield Fire Department.   

"Imagine being in a deep sleep and a bucket of cold water is dumped on you," he said. "That is kind of what it feels like."


The Minnesota Fire Initiative is a new effort by a group of Minnesota fire service advocacy organizations which is trying to educate firefighters, their families and the general public about health and mental well being of firefighters.

They want people to know there is a greater risk for firefighters in developing cancer and mental health issues than the general public. A third issue is heart disease-- the number one killer of firefighters.

The group has set up a toll-free hotline for firefighters to call about any of these issues. The number is 1-888-784-6634.

Anyone calling the line will leave a message and a peer advocate will get back to them with help and resources.  


Invisible Danger is an investigative series by Fox 9. In the last couple months the long-form stories have focused on cancer, PTSD and cardiac issues within the fire service. The stories have been viewed on social media more than 1.3 million times. Click on each to view the stories.

PTSD & Firefighters

Cancer & Firefighters