Viscous Heat Propagation (IMAGE) Ecole Polytechnique Fédérale de Lausanne Caption In some cases heat propagates within a material as a viscous-fluid flow. Credit EPFL Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.