It's one of Michigan's hottest summers on record, and the sweltering heat is taking a toll on both Dr. Pol and the local farm animals. Dr. Pol and Charles hope to save a newborn calf with pneumonia, but the thick blanket of humidity covering the area makes their mission even more difficult. Meanwhile, Dr. Brenda and newcomer Dr. Sandra struggle to help a stubborn pig give birth on a brutally hot day.

As the temperature rises in Michigan, Dr. Pol heads to a farm to help a cow that needs calcium immediately-but if he doesn't administer it right, she'll die. Then, he helps a crippled horse that has been infected by the West Nile virus. Will he treat it, or is it too late? At the clinic, a beagle has been in labor for the past 18 hours. Dr. Pol knows that the babies are too big to come out own their own. His experience shines through as he performs an emergency cesarean section, saving her life.