Prolonged heat stress reduces growth and yield in leafy vegetables like lettuce and cabbage, causes physiological stress and water loss, and leads to quality deterioration and increased susceptibility to pests and diseases. Key issues include stunted growth, leaf burn, bolting, and nutrient deficiencies. Mitigation strategies such as shade netting, mulching, increased irrigation, planting heat-tolerant varieties, and adjusting planting schedules can help manage these effects.