I have owned 3 nook colors, the first one I owned freaked out when I used a damp cloth to wipe the screen. It exhibited some strange behavior and emitted some loud static from the speaker. It would not power down or anything... finally it just went back to normal, so I took it back to B&N and then went and bought one at walmart. I took it back because I thought I wanted the Viewsonic G Tablet. But after trying it I finally bought a Nook Color at Best Buy, bought a screen protector too so that I don't have a repeat of my first NC. The screens on these things are, I believe, rather sensitive and the cold or the moisture may have played a part in your unit's behavior.