A method of measuring a gas turbine engine component of a gas turbine engine according to an example of the present disclosure includes, among other things, providing at least one gas turbine engine component including a coating on a substrate, detecting infrared radiation emitted from at least one localized region of the coating at a first wavelength in a first electromagnetic radiation frequency range, detecting infrared radiation emitted from the substrate corresponding to the at least one localized region at a second, different wavelength in a second electromagnetic radiation frequency range that differs from the first electromagnetic radiation frequency range, and determining a heat flux relating to the at least one localized region based upon a comparison of the first wavelength and the second wavelength.