The mechanical behavior of freestanding thin sputter-deposited films of Au is studied at temperatures up to 340 degrees C, using tensile testing. Films tested at elevated temperatures exhibit a significant decrease in flow stress and stiffness. Furthermore, the flow stress decreases with decreasing film thickness, contravening the usual notion that "smaller is stronger". This behavior is attributed mainly to diffusion-facilitated grain boundary sliding. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.