Broiler chickens are highly vulnerable to heat stress due to their rapid growth, heavy muscle mass, and poor thermoregulation, making temperature management a critical welfare issue.
Modern broiler genetics have created birds that are physiologically vulnerable to heat because of their extreme muscle mass and rapid metabolism. Heat stress causes suffering through respiratory distress, cardiac strain, and ultimately mortality. Chronic sub-lethal heat stress reduces immune function and increases disease susceptibility. As climate change raises summer temperatures globally, heat stress management has become a critical welfare issue requiring ventilation investment, stocking density reduction, and slower-growth breed adoption.