The miniaturisation of gas turbine engines poses significant challenges to the performance in heat management due to the close proximity of the hot and cold components. This paper examines the scale and significance of heat transfer within micro gas turbines and aims to quantify the corresponding impacts on performance and efficiency. To study these effects, a reduced order lumped capacitance heat transfer network is developed. Two different micro turbine configurations are investigated and the effect of micro turbine size and material selection is explored. The investigation shows that the choice of configuration and materials influences the impact of heat transfer on the micro turbine performance and heat management is therefore key to achieving the full potential of micro turbines. (C) 2014 Elsevier Ltd. All rights reserved.