Angling practices subject Largemouth Bass Micropterus salmoides to multiple stressors, causing homeostatic physiological disturbances. The combined effects of ambient and live well temperature on stress responses from exercise have not been thoroughly examined. Large numbers of fish required for stress experiments can be produced by intensive culture, but hatchery fish may differ physiologically from wild fish due to dietary carbohydrates. Therefore, the effects of diet, population, and temperature on stress response and health were examined. Stress responses were similar among fish fed formulated and live diets and liver health improved within 4-6 weeks. Although cortisol responses of hatchery and wild fish differed, secondary stress responses were similar. Fish subjected to simulated angling at temperatures of 17, 25, 33 °C with live well temperature differentials of -4, 0, +4 °C, had the lowest resilience to stress at the warmest temperatures, exhausting energy supplies, coincident with metabolic acidosis and poor ion regulation.