High temperature due to global warming and the overcrowding or limited space for cultured species have been evident in the aquaculture setting nowadays. In this study, physiological changes such as ventilation rate (VR), eye color pattern (ECP), and skin color were observed in red tilapia subjected to high temperature (T2), confinement stress (T3), and the combination of both stressors (T4). The VR, ECP, and skin color were monitored before the introduction of stressors (day 0) and every day after the introduction of stressors until day 15. Results showed that fish in T2, T3, and T4 had significantly faster VR, darker ECP, and more intense skin color as compared to those in the control group (T1). Increasing VR, ECP, and skin color were also recorded from day 1 to day 15 of subjecting the fish to stressors indicating that the fish were not able to adapt to the stressful environment during the duration of the study. The highest values were observed in T4 since there were two stressors present in the treatment. This only connotes that high temperature and overcrowding could really impose stress on red tilapia and 15 days was not enough for the fish to adapt to the stressful environment.