Are there any concerns with flying in fog?  I am wondering if the moisture will effect my bird.  I have seen some videos from above the fog and this morning is very foggy.  I would love to fly above it and get some shots.  I took it up for about 5 minutes to grab a quick peak, but it was too thick.  

Here was the quick peek...
Foggy Morning

Moisture!  You fly in fog and you are basically flying your quad through a fine mist of water.  Would you fly in the rain?  Eventually your quad will be wet.

Agree with nrgwise... Tried yesterday for a while, yes quad was very wet, and since then I know it was not a bright idea at all. Dried the quad home carefully with cloth and hairdryer. Never more.

I think the unit would be fine but I'd be more concerned that you'd develop a problem later, have to send the unit in and find that it's not covered under warranty because the water mark shows signs of moisture inside.

I've done the fog thing and won't do it again.  Like others have said here and elsewhere, your warranty is likely void now, as the fog probably triggered the moisture indicator on the main board.  Mine was dripping when it came down.  I went through about 200 feet of fog to get above it.  Of course, being in or above the fog is illegal in the US, but you probably know that already.

I went to a dam near my home in Blue Ridge, GA and since it was very cold (28 degrees is cold for us southerners) there was fog being generated by the difference in temps of the air/river.  I just flew a little bit below the fog layer and decided to call it a day when the electromagnetic interference was causing loss of video, magnetic compass and controller signal.  Those were brief interruptions, but enough for me to pack it up and fly another day.  All I could imagine was my p3 standard flying straight into the dam.  Below is a video I shot during one of those short flights--you can see how unstable it was even just holding position.  Very little wind that morning.  I agree with others...flying IFR in a quadcopter is not legal and not good for the health of the bird.  I'm a commercially rated pilot and know you can't file IFR in one of these just yet.  :-)

Hi , Shawnide
I know it's a extraordinary experience to fly in the mist . It's so mysterious and beautiful  . But it's not recommeded to do that as  shells are breathable .  Please take care of that !

Great advice guys... My bird didn't have any moisture when I pulled it in, due to the small flight.  I'm glad I posted this.