Temperature management in a gas phase micro-analytical system and thin silicon solar cell is critical for chromatographic selectivity of volatile organic compounds (VOCs) in moderately complex mixtures and bowing phenomena, respectively. As part of an effort to develop a high chromatographic resolution micro-gas chromatography (mGC) system, in this report we present the design based on thermal analysis, fabrication, thermal operation, and preliminary test results of a microscale passive preconcentrator/injector (mPPI), which enables detection of compounds at low concentrations by enhancing their signals. In addition, we report the thermal effect on bowing of Si solar cell with respect to the rate of heating and cooling and the recrystallized layer thickness of Si and Al as a function of temperature and heating time. A lumped heat transfer model is used to analyze the device design of a micro-analytical system and the bowing of silicon solar cell numerically. This approach is promising for enabling a high performance mGC system incorporated with our state-of-the-art passive preconcentrator microdevice and achieving high production rate of the thin silicon solar cell with our proposed numerical heat transfer model.