Heat stress is a critical welfare challenge for broiler chickens during summer, with high temperatures causing severe suffering, reduced growth, and elevated mortality in poorly ventilated sheds — and climate change is making this problem worse.
Heat stress in broilers causes acute suffering through dyspnoea, exhaustion, and cardiovascular collapse in severe cases. Chronic sublethal heat stress impairs welfare through reduced activity, altered social behaviour, and persistent discomfort. Producers in hot regions must invest in adequate ventilation infrastructure and backup power systems to prevent catastrophic mortality events during power outages. Genetic selection has produced birds that generate more metabolic heat, increasing vulnerability. Selecting for heat tolerance alongside other production traits is an underexplored genetic welfare intervention. Reducing stocking density during hot periods, providing cool water continuously, and adjusting feeding schedules to cooler parts of the day all reduce heat stress burden.