By Jamie Thompson
FireRescue1 Editor
 Photo courtesy of Marino di Marzo Components of the device, attached to the SCBA. |
Turnout gear has come a long way. From the rubber coats of the 19th century to today’s high-tech materials, no one can argue the modern firefighter is not better protected against the extreme temperatures that come with the job.
But for many, the advances in protective clothing have had a downside, too. The 21st century firefighter can enter further and further into the fire, often to the point of no return.
This has led experts to come up with a device that works in a similar way to the SCBA low-air warning bell — except this one tells firefighters when their actual gear simply cannot protect them any more.
For the past two years, safety engineers at the Fire Protection Engineering Department at the University of Maryland have been working on the heads-up temperature display.
Their research has centered on the thermal response of gear and how to timely alert firefighters to excessive heat exposure.
The result of their efforts is a device that has just gone into field testing, contracted by NIOSH, for six months with the Prince George’s County, Md., Fire Department.
“We hope we can implement this sensor within the fire service so that people will have thermal ability information similar to knowing how much air they have,” said Professor Marino di Marzo, chair of the engineering department behind the project.
Heads-up unit
The sensor is designed to be incorporated into a firefighter’s head-ups display unit.
Seemingly similar devices currently on the market only respond to the actual current temperature. But the new prototype aims to accurately predict what it will be if the firefighter remains in the existing conditions.
In the past few years, there have been instances of firefighters suffering severe burns inside their gear without any apparent damage to the actual clothing itself, which di Marzo said is precisely the issue his team has tried to address.
“I believe there is a significant need for educating the firefighter on what the gear does and what the limitations are,” he said. “The gear behavior is not intuitive and requires some detailed insight in order to be understood.”
The Fire Protection Engineering Department’s research focused on the time delay there can be in the firefighter’s perception of their environment. Simply put, exposure can already be significant by the time a firefighter first perceives it and can worsen in the minutes that follow, even when they leave the fire scene.
“Essentially, if you’re going into a hot room, you won’t notice it until a couple of minutes. Once you actually start to feel warm, it’s kind of too late,” di Marzo said. “The gear has soaked up so much heat that it’s getting warmer and warmer for the next several
minutes or so and can even burn you. But often you’re not aware of it until it’s too late.”
Di Marzo’s team worked on an algorithm for the sensor that can predict what the amount of heat stored in the gear will rise to if it remains in the same environment.
 Personal protective clothing is designed to give a degree of protection that will allow you to extricate yourself from the situation when needed and into a safer environment.  | ||
| — Bruce Teele, NFPA | ||
It calculates whether the temperature will exceed a certain threshold up to 10
minutes further down the line, and will accordingly send signals to the firefighter alerting them as to how long they can safely remain where they are.
“The way it’s been configured is kind of like an air tank alert. This one has four lights; four lights means you can stay in for four minutes and so on,” di Marzo said.
“When all four lights flash it means the gear has heated up to beyond what you can tolerate.”
Manufacturer talks
Once the field testing currently under way is completed, di Marzo said the next step is to talk with SCBA manufacturers to see which will be interested in using this device in their equipment.
Di Marzo said he is confident the device could become commonplace in the fire service in the next few years, mainly because of the concerns that already exist about modern turnout gear being too good in some respects.
“Some people do lament sometimes about years gone by. Especially around the ears and neck you didn’t have so much protection so you could feel the heat there.
“If you started getting a tingling on the top of your ear, then you would know you should stop and get out.
“Today with Nomex hoods you never feel anything and by the time you do it may be too late.”
The NFPA has been looking at similar devices for about the past 15 years, according to Bruce Teele, a senior emergency services safety specialist at the organization.
“The biggest issue we had was heat sensors that saw convective heat were very good at detecting the convective heat but not very good at seeing radiant heat, and vice versa.”
What makes di Marzo’s team’s device different is that it measures the temperature of the cloth’s outer layer, rather than the convective or radiant heat of the air.
“If it keeps either the incident commander or safety officer or individual firefighters aware of their environment and tells them with sufficient time that they have to change the atmosphere or get out of there then it could be a worthwhile thing,” Teele said.
In addition, Teele said, it is vital that firefighters remember that the advances in turnout gear are not necessarily about allowing them to stay in dangerous conditions for longer periods of time.
“Personal protective clothing is designed to give a degree of protection that will allow you to extricate yourself from the situation when needed and into a safer environment,” he said. “If you’re caught in a serious situation, you have some extra seconds to get yourself out of there.”