Thermex® is a unique temperature indicating material. As thin as a standard sheet of paper, Thermex® changes color to reveal relative temperature distribution between any two contacting surfaces. Upon exposure to temperature the Thermex® sheet instantaneously and permanently changes color. The intensity of that color is directly related to the temperature it was exposed to, allowing Thermex® to reveal spot high or low temperature zones. Thermex® is inexpensive, precise and disposable.