My Palm Centro is freaking out. Help please!?

Last week I accidentally dropped it for a few seconds in water, it wasn't totally immersed but the battery and sim card got wet. When I tried to turn the phone back on, the Hotsync application kept popping up and wouldn't allow me to go to any other applications, make calls, etc. However I just took the battery out and let it dry for about 8 hours and my phone was working again. But... today it was about 90 degrees outside and the phone was sitting right in the sun for a few hours, then it started doing the same thing with freezing on Hotsync and blocking any other applications from being opened. Is there anything I can do? Is it just that the battery fried or what?!