A thermal infrared camera attachment for smart phone

Seek Thermal Camera and a Motorola X smart phone. Photo by Bill Gabbert.

A thermal infrared (IR) camera that attaches to a smart phone is now available that could be useful for firefighters. The device, smaller than your thumb, connects to the USB or lightning plug on certain newer models of cell phones.

Everything (animals, humans, objects, water, etc.) emits infrared waves based on its temperature. An IR thermal camera measures these waves, which are invisible to human (or animal) eyes, and converts them into images.

We bought the new $250 Seek Thermal infrared camera to evaluate its effectiveness in helping wildland firefighters find lingering smoldering areas during the mopup stage of fire suppression. Under trees, organic material or duff can continue burning below the surface for days, weeks, or months and does not always produce smoke that can tip off a firefighter that the area needs attention. A still burning area that is missed can sometimes flare up and cause problems, possibly throwing burning embers across the fire line resulting in a slopover or spot fire with the potential to do serious damage.

Thermal cameras have traditionally been very expensive, which limited them to military and governmental applications. In the last ten years new, lower cost ($3,000-­‐$5000+) industrial thermal cameras have emerged. They have been primarily used by police, firefighters, and contractors. Structural firefighters have used them to detect fires that are behind walls or ceilings. IR cameras can’t see through objects, but they can detect a wall, for example, that has been warmed by hidden combustion. A fire that is smoldering in deep duff in a wildfire will heat the surface of the ground, making it visible to an IR device.

Some of the wildland firefighters that have been around for a while might remember the thermal IR detector that looked like a flashlight. It had no viewing screen, but simply emitted a tone when heat was detected. I believe the pitch changed as the temperature increased. I don’t know if those are still being used. Does anyone remember what the cost of those was?

The Seek Thermal infrared camera can view long wave infrared (7.2 to 13 microns), has a resolution of 206 x 156 pixels, a 36-degree field of view, can detect temperatures between -40F (-40C) and +626F (+330C), and weighs 0.5 ounce.

At $200 the Seek Thermal infrared camera is far less expensive than other thermal infrared cameras. For example, FLIR makes many models of IR cameras. Their E4 has a resolution of 80 x 60 and sells for $995 at Amazon. The FLIR E5 with 120 x 90 resolution will set you back almost $1,500. The company recently developed the FLIR ONE, which like the Seek Thermal works with a smart phone, but is a much larger case-type design which fits entirely around the phone. It sells for $349, has a resolution of 80 x 60, and can only detect temperatures of 0 to 100C. The FLIR ONE will work with an iPhone with a lightning connector; there is no Android model.

The Seek Thermal is available in two versions: Android and IPhone. The Apple model is compatible with the iPhone 5, 5c, 5s, 6, and 6+ running iOS7 or iOS 8. The Android version will work with devices having microUSB connectors running Android version 4.3.1 (Jelly Bean) or later that support USB Host Mode (also called USB On The Go or OTG). The company says it has been tested extensively with the Galaxy S4 and S5 and the Moto G and X phones.

To use it, download the Seek Thermal app from the Apple app store or the Android Google Play store. I tested it on a Motorola X running Android 4.4.4. Helpfully, there were several prescribed fires being managed in Wind Cave National Park where I was able to find realistic conditions that wildland firefighters might run across.

 Cold Brook prescribed fire
This photo of Unit #3 of the Cold Brook prescribed fire was taken four days after the IR image below, from approximately the same location. Unlike the other pairs of images this photo was taken with a different camera at a different time than the pairs of Seek Thermal IR/smart phone combination photos farther down.
thermal IR image of prescribed fire.
An IR image of approximately the same area as the previous photo. This was taken October 23, 2014 with the Seek Thermal IR camera shortly after some of the area in the image had been ignited on the Cold Brook prescribed fire in Wind Cave National Park.

The IR image above was taken about 800 feet from the prescribed fire.

The IR camera was set to display the maximum and minimum temperatures detected. Interestingly, the minimum is in the area of the sky, showing -2 F. The maximum is displayed as 189 F.

The IR camera can be set to show the following items on the image:

  • Temperature in the middle of the image; (temperatures in Fahrenheit, Kelvin, or Celsius);
  • Maximum and minimum temperatures anywhere in the image;
  • Only areas that have a temperature within the min/max range that you set;
  • No temperatures displayed;
  • Lat/long;
  • Date and time;
  • Options for several different “color pallets” to represent temperatures;
  • A  watermark for Seek Thermal, which by default is turned on, unfortunately. But, it’s easy to turn off after cruising through the menus.

In addition, you can choose to display on the screen both the IR image and a true color “normal” image taken by your phone’s camera. You can drag a slider across to emphasize either.

You can take photos, of course, with the device. If you have the option selected for both regular and IR images, it will take and save two photos. If you have the temperatures displayed, they will also appear on the regular non-IR images.

Videos are also possible, as you can see below, in this two-second thermal infrared video of firefighters near a small area of burning grass on the Cold Brook prescribed fire in Wind Cave National Park, October 23, 2014. The firefighters were from the Alpine Hotshots, preparing to ignite the prescribed fire.

More examples of images are below, showing pairs of  normal photos followed by the IR version of the same area.

IR Cold Brook prescribed fire
Note the tree’s shadow, which had been shielded from the sun, and compare it to the same area in the IR version below. The photographer’s shadow on the lower-right had only been present for seconds, and had not yet affected the temperature of the ground.
IR Cold Brook prescribed fire
IR version of the previous image. There was no visible smoke in this area. The image was taken at 3:02 p.m. MDT on a cloudless day. The air temperature, I believe, was in the 60s, but the sun heated many objects to around 100 F.  The only area in this image that was still burning was the spot near the displayed temperature of +194 F.

The greater the difference in temperatures between the areas that are burning and everything else, the easier it will be to spot heat created by fires. That is why the U.S. Forest Service fixed wing IR planes fly and map fires at night, rather than during the day when the sun heats objects on the ground.  I found that the displayed temperatures on the screen were more helpful than depending on the colors representing extreme heat.

IR Cold Brook prescribed fire IR Cold Brook prescribed fire

The two images above were taken about 15 feet from three firefighters. They were not aware of this hot spot and even when I pointed toward it from 15 feet away they were not able to see it, since there was no smoke. After we walked over to the area and stood over it, they saw that it was hot, and mopped it up with scraping tools.

IR Cold Brook prescribed fire

IR Cold Brook prescribed fire
IR image with the camera set to only highlight areas with a temperature higher than 140 F.

The single image below shows how the IR camera system got confused when the temperatures exceeded the range of the sensor, which is -40 F to +626 F. Often 6- and 7-digit positive and negative numbers were displayed when active fire was detected.

Infrared Cold Brook prescribed fire.
This single image shows how the camera can get confused when the temperature exceeds the range of the sensor, which is -40 F to +626 F.

We used the IR thermal camera for a hour or so at a time and did not notice any major depletion of the battery, except when we turned on the location option where the lat/long would be displayed. This triggered the GPS into action, which can have a large effect on a battery. So if it is used extensively on a mopup shift, especially with lat/long turned on, there should be a way to either recharge or replace the battery, or simply transfer the camera to another phone. I can’t see a major need to have the location mode turned on while mopping up. But if you’re finding lightning fires or abandoned campfires from a helicopter, it would be extremely useful

IR thermal modes
Thermal modes on the Seek Thermal IR camera.

As you can see in the list above, there are eight different “thermal modes”, depending on what you are imaging. Unfortunately, there is nothing even close to what you might run into on a wildland fire.  We did not experiment with these modes, and just used the default “skin” mode while taking all of these photos. It is possible that other modes could work better on a wildfire.

We hope the developers will create a “vegetation” or “wildland fire” mode for the next revision of the app.

The company does not say anything about using the device on wildfires,  but they list numerous other applications, including:

Safety and Security

  • Scan the dark parking lot walking out to your car to see if there are any people (or animals) around.
  • See what is making that noise in your back yard at night.

Home Improvement

  • See where the heat is leaking from your house and identify leaky windows, walls missing insulation, and other sources of energy loss.
  • Trace water damage up a wall or across a ceiling to its source.
  • Identify the location of clogs in pipes (just run hot water down the pipe and trace where it goes and stops).

Pet Owners

  • Ensure that there aren’t any other animals in the yard before letting your dog out at night.
  • Find your dog or cat at night.
  • See where on the counter or furniture your animal has been sleeping while you were out.


  • Measure the heat distribution across your BBQ or griddle.
  • Instantly measure the surface temperature of food.
  • Measure level of propane in BBQ tank


  • See structures and vessels on the water at night.
  • Find objects/persons that fell overboard.


The camera displayed ridiculously wrong temperatures when very hot or flaming areas were imaged. But usually those areas are very obvious, and can be easily seen without any hand-held gadget. I was able to detect with the IR camera still burning areas that could not be found by a human, without them bending over, taking off their glove and holding the back of their hand just above the surface. Some of the areas found with the device could not even be detected with the back of the hand, unless the area was first stirred up with a scraping tool, to expose some of the hotter burning areas.

More real world experimentation by firefighters is needed, but this $200 gadget might make mopping up more efficient, and could result in fewer missed areas that need attention. It would be most useful near a fire line where it can be crucial to obtain 100 percent suppression.

Another use that could be explored is its effectiveness from a helicopter to detect a small lightning fire or abandoned campfire that would otherwise not be seen.

The Android version of the Seek Thermal IR camera can be purchased at Amazon.

Seek Thermal Infrared camera and a Motorola X smart phone.
Seek Thermal Infrared camera and a Motorola X smart phone. All photos in this article were taken by Bill Gabbert.

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Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

8 thoughts on “A thermal infrared camera attachment for smart phone”

  1. i have the new tradies phone model t83. will the thermal imager work onit and how do i purchase 1 unit and how much

    1. Thanks, Joaquin. I was not aware of the anemometer that can be plugged into a smart phone. If they add temperature and RH sensors, it could REALLY be useful. And the software could retain the data on the phone, displaying graphs showing the trends, hopefully, even after the unit was disconnected. And… you should be able to email the accumulated data to others that need it, such as the NWS for their spot weather forecast, and the Planning Section and Incident Meteorologist at a large fire.

  2. This seems to fill the need for hotspot detection on the ground. After reading some of the suggested uses for this item on the Amazon page, I remembered another camera that allows similar IR viewing. When I want to use IR to see at night, I use the Nightshot feature on my Sony video camera. I’ve never tried it on a fire, but it’s high resolution and sensitivity would put it far ahead of this unit, if it worked. I don’t have access to a wildland fire at the moment, or I’d post a review; maybe someone else has tried it, or can give it a trial and let us know how it works?
    Interesting side note: most common digital camera sensors are sensitive to IR, but have an IR filter to block it. There are websites showing how to remove this filter and turn your regular digital camera into an IR camera.

  3. Interesting tool….
    This sensor could help ground pounders but unless they are properly trained on infrared i believe this could cause some false readings. Finding the big hotspots is easy, but the small one hot spots requires proper training, understanding of the sensor, and a higher sensor sensitivity.

    I have used infrared tools for a number of years, handheld and gimbal mounts, but this past spring I took an infrared training course and realized how much I didn’t know and was likely wasting time and money.
    What I’m getting at is be cautious on putting all your faith in new tech because a number of variables come into play, most importantly the infrared operator.


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