Heat stress in cattle is a growing welfare and production crisis as climate change intensifies summer temperatures. Understanding the physiology of bovine heat stress enables effective prevention and emergency response.
Heat stress causes genuine suffering in cattle beyond production losses. Panting to dissipate heat is energetically costly and physically distressing; respiratory alkalosis from excessive panting causes metabolic disruption. Crowding at water sources leads to aggression and injury. Pregnant cows under heat stress have impaired placental function, causing fetal growth restriction and calf welfare impacts that persist after birth. The welfare impact of heat stress is often invisible to producers focused on production metrics, but is measurable through behavioral, physiological, and health outcomes. Climate change is extending heat stress seasons and intensifying peak events, making thermal management increasingly central to cattle welfare across temperate and tropical production regions.