Heat stress in livestock is a growing welfare crisis as climate change raises temperatures and extends heat seasons. Understanding and addressing heat stress is both a welfare imperative and a production priority.
Heat stress causes physiological and behavioral suffering that, when severe, leads to heat stroke and death. Even sub-lethal heat stress causes chronic welfare compromise: animals with elevated core body temperature show reduced feeding, altered behavior, immune suppression, and reproductive failure. In confinement systems where behavioral thermoregulation is impossible — a pig in a gestation stall cannot seek shade or wallow — heat stress welfare harm is entirely dependent on the cooling infrastructure provided. Climate change is making this increasingly urgent: production systems designed for historical temperature ranges are becoming inadequate as extreme heat events become more frequent and severe. Welfare-protective climate adaptation in livestock farming requires investment in cooling infrastructure, adjustment of stocking densities, and in extreme cases, reconsideration of production regions for heat-sensitive species.