Heat generation in metals during high‐strain‐rate plastic deformation was investigated. Experiments were designed to measure the partition of plastic work into heat and stored energy during dynamic deformations under adiabatic conditions. A Kolsky pressure bar was used to determine mechanical properties at high strain rates while a servo‐hydraulic material testing system was used at low strain rates. For dynamic loading, in‐situ temperature changes were measured using a high‐speed infrared detector. The dependence of the fraction of plastic work converted to heat on strain and strain rate was determined for an aluminum 2024‐T3 alloy and α‐titanium. The flow stress and the fraction of plastic work converted to heat for 2024‐T3 aluminum alloy were found to be a function of strain but not of the strain rate while they were found to be strongly dependent on strain rate for α‐titanium.