Impulse thermal energy method (ITEM) as modification of the thermal energy method that is successfully used for finishing is considered for application to thermoplastics. The chapter focuses to highlight the basic principles of the thermoplastics treatment by acting heat fluxes inherent to ITEM providing the time-controlled production of combustion species. The properties of thermoplastics and the requirements for their treatment have the greatest impact on processing settings. Thus, the questions of the choice of the preferred fuel mixture, the type of its ignition, and combustion have been studied. By means of numerical situating, the processes of melting and healing of pores during processing are investigated. A method of defining processing settings has been developed, taking into account the limitations on critical temperatures. The promising possibilities of ITEM in relation to the processing of thermoplastics parts obtained by additive technologies are outlined.