The benefit of vapour chambers, commonly known as flat plate heat pipes, in electronics thermal management is that they can significantly reduce the conduction resistance present in the base of large metallic heat sinks. This paper considers an experimental study in determining a vapour chamber heat pipe performance. Using an IR thermal imaging camera, temperature measurement and distribution on the evaporator surface of the heat pipe was recorded. To verify the validity of this technique, steady state and transient analysis of comparative experiments were performed on two vapour chamber heat pipes (a fully functioning vapour chamber heat pipe and a failed vapour chamber heat pipe) and on a solid block of copper. The test-rig set up as well as the experimental results are presented in detail.