One of the most common misunderstandings of technology I see on many of these paranormal themed reality shows has to do with how the data gathered by the thermal device is interpreted.
Below is a thermal image taken from a quick Google search:
On the right side of the image is a data range indicating the heat radiating from the captured object. In this case, the range is from 23 degrees centigrade to 11 degrees centigrade. It is important to note this scale because images appearing on the thermal device that may seem much warmer than their surroundings may, in fact, be much closer in actual surface temperature. Again, referring to the picture above, the front of the house seems much warmer than the roof, as indicated by the orange hue as compared to the purple hue of the roof. However, by looking at the scale, we can tell that there is really only about a 3 degrees centigrade difference (which is only approximately a 8 degree difference — 18 degrees centigrade is about 64 degrees Fahrenheit compared to 13 degrees centigrade which is about 56 degrees Fahrenheit).
Similarly, this image shows a dog lying on the ground. Notice the scale, however. At most, this thermal device is measuring the captured data on a 9 degree Fahrenheit span. This means that even though the dog may seem much hotter than the floor based purely on the image, it is no more than 9 degrees warmer. Applying the scale to the picture, we can see that the “dog” may really only be about 5-6 degrees warmer than its surroundings.
The most important aspect of analyzing collected data is understanding how to read the data. Next time you are watching one of these reality shows and the investigators come across a thermal hit that seems to be “on fire” compared to the surroundings, look to see if they’ve included the scale in the shot, and take note of how much warmer the object or area is compared to its surroundings, rather than relying solely on the color distinction.