The linguistic, psycholinguistic, and neural processes underlying simultaneous interpreting and translation have attracted widespread interest in the research community. However, an understanding of the cognitive load associated with these bilingual activities is just starting to emerge, and the underlying behavioral and physiological mechanisms are still poorly understood. In this article, we describe a promising interdisciplinary approach to assess the behavioral and physiological indices of cognitive load during interpreting and translation in laboratory and simulated workplace settings. In this context, we emphasize the importance of ecological validity and explain how comparisons between authentic non-standard input and edited English versions of the same stimuli can be used to evaluate cognitive load while controlling for the general cognitive demands associated with interpreting and translation. The perspective we present in this article might pave the way for a clearer understanding of the multifaceted dimensions of cognitive load during simultaneous interpreting and translation as well as during the processing of English as Lingua Franca.