Phone got a little wet today, how long should I wait to turn it on?

I was hiking today and I had my nexus in a mesh pocket on the side of my backpack. I slipped on a rock and fell into the stream for a second before jumping out and immediately pulling out my battery. It was sort of protected by the pocket it was in and I'm not sure if it was ever submerged but it was definitely splashed significantly.The screen had been facing out and that seemed to be where most of the water was and the back battery area seemed pretty dry so I'm hopeful nothing got inside but I'm worried about the speaker and the volume/power ports. I toweled it off and I cant see any water anywhere but I'm still worried about it. I have it sitting in rice at the moment, how long should I leave it before I attempt to do anything and are there any other things I could do to help?