What is a one-sentence summary of the following article?
In the event you get your cast wet, you should make an effort to dry it quickly. This can reduce the harm to the cast, and eliminate your risk of infection.  Use a hairdryer to dry a cast. Always use the cool setting. The hot or warm setting could cause a burn. You can also try a vacuum cleaner hose, if you do not have a hair dryer. A cast may have to be replaced if it gets wet. If you accidentally got water on your cast, call your doctor right away. Make an appointment as soon as possible. Water could seep under the cast, which can cause infection to the skin below. Fiberglass casts are more resistant to water, and if their surface gets wet it can usually be easily wiped off. However, water can still get under a fiberglass cast, potentially causing infection. Even if you have a fiberglass cast, it's a good idea to give your doctor a call in the event it gets wet.

Summary:
Dry casts after they get wet. Call the doctor shortly after a cast gets wet. Be careful even when using a fiberglass cast.