Resumen: Personal Comfort Systems (PCSs) have emerged as an innovative solution to address variable individual conditions that traditional comfort models excluded. This study investigates the impact of the simultaneous application and use of three PCSs in real office environments on an occupant’s thermal, light, and air quality perception and seeks to understand different environmental stimuli behind personal actions and behaviors. It uses qualitative and quantitative monitoring of specific environmental conditions and individual actions of 72 participants in four office buildings in different climatic zones of Chile in summer and winter. The PCSs tested differ in their costs, technological level, usability, and portability. The results show that 85.5% improved their perceived comfort by using the PCSs, although not from simultaneous use, but rather from the use of one system over another. The desk fan stands out as having the highest acceptance and utilization rate. However, certain environmental conditions cause opposite actions: limited lighting control or little daylight causes the fan to be turned on. The present study’s data could contribute to a new environmental comfort model for shared office spaces, fostering significant improvements in occupant satisfaction and energy efficiency. This practical and scientific research is of interest to architects, designers, and stakeholders from the construction production field.