Plots showing a. Predicted renal hyperplasia increases with temperature, with steeper responses at higher parasite loads, indicating that warming disproportionately amplifies pathology in heavily infected fish. b. Predicted renal hyperplasia increases with parasite load, and this effect strengthens at higher temperatures, while remaining weak under cooler conditions (no PKD symptoms). c. The interaction surface shows that the highest predicted renal hyperplasia occurs where elevated temperatures and high parasite loads coincide; the original data points are shown in grey. Ribbons in a, b represent a 95% confidence interval and across all panels, the dashed line resembles the temperature threshold, and the dotted line resembles the threshold for PKD.