Heat stress costs the swine industry about $900 million each year by reducing pig growth and reproduction. When pigs get too hot, they eat less, breathe faster, and move more blood to their skin to cool down. If this is not enough, their body temperature rises and they experience heat stress. This causes pigs to focus on survival instead of growth, reproduction, or milk production. Researchers study heat stress to find better ways to reduce its effects, including understanding how it may affect male and female pigs differently.