The stabilization of a flame in a narrow quartz tube strongly depends on the thermal environment. To determine heat transfer and better understand the stabilization mechanisms of a flame in a narrow channel, wall temperature profile measurements are needed. The Laser Induced Phosphorescence (LIP) is used with the intensity ratio method to obtain temperature distribution of the outer surface of a 5mm inner diameter quartz tube within which a lean premix methane/air flame is stabilized. This study evaluates the ability of this method to capture a large temperature gradient on a small volume with a high curvature and compares the use of two phosphors.