Plasma-facing components (PFCs) for fusion reactors and high heat flux heat sinks for electronic applications, are usually subjected to a peripherally non-uniform heat flux. The configuration under study is related to these applications and consists of a single-side heated circular-like cross-section test section (TS) with a circular coolant channel bored through the center. The TS has a heated length of 180.0 mm and has 10.0 and 30.0 mm inside and outside diameters, respectively. It was subjected to a constant heat flux on one side only, and the remaining half of the circumferential surface is not exposed to a heat flux. The inlet channel water temperature was held constant at 26.0 degreesC, the exit pressure was maintained at 0.207 MPa, and the mass velocity was 0.59 Mg/m(2) s. The results consist of three-dimensional TS wall temperature distributions and a clear display of both CHF and post-CHF for this single-side heated configuration. These results are very encouraging in that they are among the first full set of truly three-dimensional TS wall temperature measurements for a one-side heated (OSH) flow channel which contains the effect of conjugate heat transfer for turbulent, subcooled flow boiling.