Pigs are uniquely susceptible to heat stress due to limited sweat glands and a high metabolic heat load, making cooling systems a welfare necessity in tropical climates and increasingly in temperate regions due to climate change.
Pig heat stress welfare is both an immediate daily welfare concern in tropical production regions and an escalating problem as climate change extends heat stress conditions in previously temperate regions. Pigs in temperatures above their thermoneutral zone experience chronic physiological stress that compromises immune function, reproduction, and behavioral welfare. The inability to sweat or pant effectively means heat-stressed pigs cannot self-regulate adequately without environmental intervention. Wallowing - denied to nearly all commercially housed pigs - is one of the most important natural heat management behaviors. Welfare-positive pig production in warming climates requires investment in cooling infrastructure as a welfare necessity, not an optional comfort measure.