The Sick Patch is an invention and a transdermal patch that releases complex viruses into the blood of whoever wears it, resulting in them getting very sick. When the patch is removed, the symptoms it releases vanish almost instantly. In the episode "Journey to the Center of Carl," Jimmy used it to skip school and soon enough, all of his friends did as well. However, when their parents’ treatments/homeschooling methods were getting painful and annoying, the sick patches dissolved through their skin into their blood before they could take them off. Luckily, Jimmy made a vaccine using mitochondria from one of the viruses and everyone was cured.