People living in industrialized areas spend more than 80% of their lives indoors. Indoor environment quality (IEQ) is a multi-faceted construct that encompasses various elements like thermal comfort, indoor air quality, acoustic comfort, and visual comfort. While research in the fields of building science has made strides in defining what constitutes a productive space, most studies examine the IEQ factors in isolation. Given that cognitive performance is crucial to human productivity and learning, this study investigates the combined effects of concurrent discomfort from three IEQ domains – thermal (temperature), acoustic (noise), and visual (glare) – on cognitive performance. In two field labs, 32 participants were exposed to eight combinations of IEQ conditions. Participants’ subjective assessment on comfort and Self-Estimated Performance (SEP) is analyzed. Participants reported greater acoustic discomfort in noisy environments, and this discomfort was significantly amplified in warmer conditions (p < 0.05). SEP showed significant effect only for a specific combination of conditions across all the tested domains. These findings highlight the importance of considering cross-domain interactions in IEQ research and underscore the need for further investigation into objective measures of cognitive performance under combined discomfort conditions.