Heat affects vegetables in the following ways: 1. Texture Change: Heat softens vegetables by breaking down fiber and cell walls. 2. Color Change: Prolonged heat causes loss of bright colors due to pigment breakdown. 3. Nutrient Loss: Overcooking leads to the destruction of vitamins (e.g., vitamin C). 4. Flavor Development: Cooking enhances flavor but excessive heat can reduce it. 5. Shrinkage: Water loss during cooking reduces the size of vegetables. Proper heat application ensures better flavor, texture, and nutrient retention.