Livestock Heat Stress: Welfare in a Warming Climate

Rising global temperatures are increasing the frequency and severity of heat stress in livestock. Heat stress causes significant suffering and is among the most pressing climate-linked animal welfare challenges.

Key Facts

Cows begin experiencing heat stress at temperatures above approximately 25°C combined with high humidity.
Heat stress in dairy cows reduces milk production by 10-20% and causes behavioral changes including reduced eating and movement.
Broiler chickens are particularly vulnerable — their genetics for rapid growth impair thermoregulation.
Pigs have no functional sweat glands and rely entirely on behavioral and respiratory cooling.
Estimated annual losses from heat stress in US livestock alone exceed $2.4 billion, yet animal suffering is rarely quantified separately.

Welfare Considerations

Heat stress is one of the clearest examples of how climate change translates into direct animal suffering. Temperature and humidity combinations that cause discomfort, physiological strain, and behavioral changes in livestock are becoming more common and more intense. Animals in intensive systems — with limited space, no shade, and no control over their environment — experience the most severe heat stress. While economic incentives push producers toward mitigation (cooling systems, shade structures, adjusted feeding times), welfare should be the primary motivation. Climate adaptation in agriculture must include animal welfare as a core outcome.

What You Can Do

Support farm policies that require minimum shade, cooling, and ventilation standards for livestock.
Choose meat, dairy, and egg products from farms with documented heat management programs.
Advocate for climate adaptation funding that includes animal welfare as an explicit goal.
Reduce consumption of animal products from intensive systems with poor heat management infrastructure.