"Mazu denchi wo hazusu koto."
The first thing to do is remove the battery.
If you ever get your cell phone wet, first remove the battery. Then dry well in a cool dark place. Do not, under any circumstances, put the battery back in or turn the power back on until you are absolutely sure the phone is completely dry.
That's what the Pumpkin Daddy says, anyway. He works in the industry, you should know. I didn't know this until he mentioned it while having dinner with my friends I and Y.
Several months later, Y accidentally dropped her cell phone in a cup of tea. She did exactly as the Pumpkin Daddy said, and saved her phone along with the phone numbers of all her friends and relatives. (It's not so much the phone itself that's important, it's the data inside. At least, for me, anyway. And most of the people I've talked to.)