The local heat flux and temperature on the boiling surface are measured to determine the heat transfer mechanism in nucleate pool boiling. Using infrared thermometry, the temperature distribution can be measured when mid-wave(3-5.5um) optical access to the surface is possible. The heat flux is calculated by the heat equation with this temperature information. The contact line length density(CLD) and the time-averaged wetted area fraction(WF) are also measured for an infrared opaque indium-tin-oxide surface over an electrically heated silicon substrate which is transparent to infrared. With this information, the dominant heat transfer mechanism during the nucleate pool boiling of water is evaluated. In conclusion, the convection heat transfer on the liquid area based on the micro-convection model is the predominant heat transfer mechanism during the nucleate pool boiling of water.