The easiest way to record the temperature fluctuations associated with hauntings is to use a thermometer. The most common type used in ghost hunting is a basic infrared thermometer gun. These point-and-click thermometers don't require any contact with the object they're measuring the temperature of. You simply point the device and press the trigger.

Unlike regular glass or mercury thermometers, infrared thermometers don't measure air temperature; they only measure the surface temperature of the object they are pointed at. Therefore, if someone reports feeling cold, an infrared thermometer won't give you an accurate reading of the temperature around the person.

Another pitfall of infrared thermometers is that they are unreliable at a distance. This is because most commercially available infrared thermometers have a distance-to-sight ratio of 12:1. This means that if you are holding the gun 12cm from an object, then the target area that the gun is looking at is 1cm...