A common fear when dealing with an overgrown backyard is running into poison ivy. If you have ever been exposed to poison ivy, or any of its cousins, poison oak or poison sumac, then you know how painful it can be. The problem with these plants is that the oil that comes off of them can stick to your clothing and then spread to your skin when you handle the clothes. Wherever the oil spreads it can cause an allergic reaction.
To avoid being exposed, you should make sure that you are careful in areas where you suspect that they might be growing. You should wear long sleeves and pants, and once you are done working in the area, you should drop them straight into the washer without touching them.
If you have cleared out some undergrowth and you suspect that there might be some of these plants mixed in, you should also avoid burning it. The smoke that these plants give off can actually cause a more serious reaction than touching the plant itself, causing respiratory problems.