Heat stress is a leading cause of welfare compromise and mortality in commercial poultry, particularly as climate change increases the frequency and intensity of extreme heat events.
Heat stress in commercial poultry represents a convergence of production system vulnerabilities and climate change consequences. Modern broiler breeds, selected for rapid muscle growth, have relatively poor heat tolerance. In improperly ventilated or overcrowded houses during summer heat events, chickens experience hyperthermia — body temperature exceeding critical limits — which causes distress, immune suppression, and death. Climate change is making these events more frequent and severe, creating an urgent need for both immediate management improvements and longer-term system redesign to cope with a hotter world.