My salamander got out about a month ago, I looked all night with no success. I told my girlfriend before I went to bed.
In the morning I was awoken to her yelling at me to come get it while it was walking under the heaterz. At the time we had no furnature so it was easy to spot. A fully furnished house is alot of space to cover. An appartment is almost a lost hope. Good luck still.
check warm places around your room is all I can say right now.