Thermal Imaging: 5 Common Mistakes Of Thermal Imaging

Thermal imagers are continually becoming more common in firefighting operations and the list of applications for which the devices are being used continues to grow. From search and rescue to fire attack to size-up and overhaul to motor vehicle accidents and beyond, thermal imagers help firefighters to do what we can’t on our own: see through smoke, identify hot spots, monitor building conditions, locate victims and much more.

While thermal imagers can certainly make the job safer and more efficient, it gets very tempting to abandon the basics. You must be disciplined enough not to abandon standard operating procedures (SOPs) and critical firefighting training tactics learned in fire school. You must stay focused on the task at hand and treat the thermal imager as the tool it was designed to be to help us do our job better and safer. Never let the thermal imager tempt you to fall for any of these common mistakes.

1. Walking straight into danger

One of the first things you were likely taught for conducting interior searches is to maintain a reference point. Right-hand and left-hand search patterns became second nature because staying on the wall gives you a common point of reference, identifies secondary points of egress and builds a mental map of the room. With this mental map, one can maintain orientation and reverse the map when the time comes to leave.

When armed with the bright, pixelated display of a thermal imager, however, we can neglect this approach. Once we can see, it is easy to think we don’t need to rely on tactile senses and discipline borne from “blindness.” The shortest distance between two points is a straight line, and with the ability to see what’s in front of us, we can walk that line. But this can allow us to walk directly into danger.

While the thermal imager should help to guide the way, what would you do if something happens to it? What if it is dropped or if the battery runs out? Without the knowledge of a reference point, it is easy to find yourself lost in the middle of the structure.

2. Relying solely on the thermal imager

Avoid tunnel vision. Although it may seem counterintuitive, the ability to see can be the very thing that blinds us on a firefighting scene by distracting us from the task at hand. The ability to see through smoke can take focus away from the reason we’re on the scene, if we let it. When entering a structure, what is important? To me, it is fivefold, in no particular order:

• Understanding the building condition

• Searching for and finding the victim(s)

• Identifying the source of the fire/heat

• Maintaining crew integrity

• Looking for a secondary means of egress in case conditions deteriorate

The desire to keep search times at a minimum by relying solely on a thermal imager can be what slows you down. Using the imager to help you to concentrate on (rather than letting it distract you from) the most important things should dramatically reduce search time.

3. Failing to understand building integrity

When entering a building, if heat or smoke conditions don’t force us to crawl, we all have the instinct to stand up and walk. Typically, it is smoke and the inability to see that demands crawling. With a thermal imager, however, we can see. When we see shades of black, white and gray beneath us, we assume it’s the floor. While it’s nice to know the relative temperature differences of the area below us, we still need to verify what the black/white is. Otherwise, we might walk in and assume the floor is solid. The black/white represents the temperature of something; not necessarily the floor.

Without a thermal imager, when we are unable to “see,” we pound the floor with an axe, halligan or pike pole to ensure that it is a stable surface before entering. With an imager, we can see a shade of black/white and assume it’s a floor. To ensure our own and our crew’s safety, however, we need to interpret the image we see on the TI display and yet still verify the surface’s integrity. After establishing physically that it is a solid surface, we can use the TI to monitor color changes to understand any changes that might be affecting the integrity of the structure.

To illustrate this in training, you can use the following example: think of what a room-temperature floor looks like on a thermal imager. The floor looks black and solid. Now, put an oven-hot cookie sheet on the floor. The white rectangle looks like a hole in the middle of the floor, but it isn’t, as hitting it with a halligan or axe would tell you. You can stand right on it and not fall through the hole. The thermal imager tells you part of the story; with training principles, the full story comes to light.

4. Failing to look up

As we all know, seeing is powerful. If, however, we’re thinking of the thermal imager only in terms of search and rescue (SAR) – to use it to look for a person – we may be encouraged to limit the true capabilities of the imager. When in SAR mode in search of a civilian victim or a fallen firefighter, we know that the person will be down low – perhaps on a chair or on the floor. Because of this, we instinctively angle the thermal imager down to the floor to look for the victim.

When we are engaging an imager solely for this purpose, we are not using the tool as it is designed and could miss other important information that would aid in our search-and-rescue assignment. We could be putting ourselves – and therefore the victim’s chance of recovery – in jeopardy by not paying attention to building integrity by scanning the condition of the walls to examine for warning signs of collapse and to understand the building integrity.

The thermal imager is not even the only part of our equipment that is pushing us to look down. Over time, we’ve learned and conditioned ourselves not to look up, because the brim of the helmet hits the airmask and we normally can’t see anyway, so it was just easier to crawl with the head down. With a thermal imager, because we have additional visibility capabilities, we need to look up in order to fully utilize the tool. Even in SAR mode, we must be aware of what is around us, for our safety and the safety of the person for whom we are searching.

5. Forgetting where you came from

When entering a room with a thermal imager to conduct a search, as I said above, it’s easy to move directly from point A to point B without paying any heed to looking behind. What if the victim made her way close to the door, though? You could walk right by a victim if you are too focused on moving from where you are to where you’re going.

Even with the gift of sight with a thermal imager, when you enter the room, you still need to do a full 360. Think of it as completing a six-sided search: the wall to the left, the wall to the right, the wall in front, the wall behind, the floor and the ceiling. For egress purposes, pay attention to your entry point as you come into the room. Take a moment and look back at the point of entry so you can remember what it looked like. If there are multiple doors, I recommend using a system to note the door you entered.

A thermal imager can be a real help in this. You can use a handline to spray water on the door you just entered. This changes its color, so you can identify the door through which you entered by looking for the darker (cooler) door and not forget where you came from. By monitoring the condition of the door throughout the search, you can also be sure that the egress is still clear and that the situation in the fire hasn’t changed or else make alternate plans to get out.

Conclusion

Thermal imagers let us save victims, property and our own lives. But they must be employed in the context of safe, smart firefighting techniques. We can’t allow the ability to “see” make us blind to hazards. Incorporating thermal imaging training into all aspects of the fire service is a must. With proper and safe training, firefighters will be better equipped to use these tools in an appropriate manner. Doing so, may result in saving a life.