Extension cords are very handy in that they let you use an item wherever you need to, not necessarily wherever you have an electrical outlet. However, there are some things you want to avoid when using an extension cord. Do not run an extension cord over an area of water. This includes over a bathtub or sink or through a shower or fountain. Also, do not use an indoor extension cord outside. They do not have the same level of protection against the elements as the outdoor versions do. Never remove the grounding pin from an extension cord just so you can fit it into a two-prong outlet. Don't plug multiple extension cords together to avoid overworking the outlet. You shouldn't use multiple large power users on one extension cord. For instance, a refrigerator and portable air conditioner should not be plugged into the same extension cord.