PITTSBURGH — Firefighter Eric Feltner put on his equipment — all 80 pounds of it — one piece at a time: heavy pants and a long jacket, a clothlike-mask over his head, black boots, gloves, a hard helmet and clear goggles. Then he grabbed an 18-pound metal bar and began walking.

On this late summer day, Feltner wasn't preparing to fight a fire. He was loading up for a federally funded study to find ways to protect firefighters from suffering heart attacks.

Cardiac arrest is the leading cause of on-the-job deaths for firefighters, who are required to work their bodies hard in high, intense heat carrying heavy gear. About 45 firefighters die every year after suffering cardiac arrest in the line of duty; in September, a fire chief in suburban Pittsburgh suffered a heart attack and died while responding to a suspicious fire in an abandoned bar.

"You don't get a choice not to fight a fire. The bell rings, you go," said Dave Holster, director of the University of Pittsburgh's Emergency Responder Human Performance Laboratory and a volunteer firefighter for 20 years.

In the first phase of the multiyear study, firefighters like Feltner are walking in full gear on a slightly inclined treadmill while researchers measure their heart rate and temperature. Then different fluids, from water to sports drinks, are used to help the firefighters' lower both.

The walking helps mimic what happens to firefighters' bodies at a fire. Researchers want to find out what protocols work best to bring down a firefighter's heart rate and temperature, a process referred to on the job as rehab.

In the next phase of the study, the rehab protocols will be used at the scene of actual fires, where intense heat also will be a factor.

Holster said few fire companies across the country have solid rehab protocols, and that many departments consider a cold bottle of water and place to sit adequate.

"Even in places that do rehab and really take it seriously, there's a lack of evidence" about what's best for a firefighter's heart, Holster said.

Dr. David Jaslow, director of the Division of EMS and Disaster Medicine at Albert Einstein Medical Center in Philadelphia and also a trained firefighter, said that some firefighters don't fully appreciate the risks they take on the job.

"They roll the dice and hope that nothing will happen," Jaslow said.

Fighting a fire is like running a marathon, with intense heat, toxins and smoke added to the mix, Jaslow said. Firefighters, he said, need the same kind of attention that pro football players get when they leave the field and are attended to by trainers and given fluids.

"The whole health and safety thing in the fire service has been very, very slow to materialize over the past 25 to 30 years," Jaslow said.

The National Fire Protection Association publishes recommendations for effective firefighter rehab — such as where and how to set up specific rehab areas at fire scenes, how much fluid to administer to firefighters and when to refer emergency workers for medical help.

Carl Peterson, director of the association's Public Fire Protection Division, said standards vary from department to department.

"I think what happens many times is that fire departments don't get this started soon enough," Peterson said. The result is that rehab is initiated too late to help some firefighters, or that there aren't enough emergency personnel at a scene to fight the fire and provide for rehab, he said.

Back in the Pittsburgh lab, Feltner's heart rate quickly rises from 138 beats per minute to 158 after just a few seconds on the treadmill.

The 25-year-old will alternate between walking on the treadmill on an incline and flat until his heart rate reaches about 200.

Then, it's time to take a break and grab a drink as his heart rate is monitored some more.

Feltner said there's always a designated safety officer on the job at his fire station in suburban Pittsburgh. But that doesn't mean firefighters don't often push themselves.

"You do hit a certain point where you're exhausted but you know it's an important job so you have to do it," Feltner said.

Holster said he's known firefighters who have had heart attacks that ended their careers, or worse, and he believes the research will make a difference.