Wet floor on driver's side.

[Mercedes Guy]

This isn't a Mercedes question, but I was wondering if anyone could offer an explanation. I got a call from a relative last night in regards to his 2000 Toyota Camry. He said that when he got into his car yesterday the driver's side floor was soaking wet. The passenger side was completely dry. He said that the car hasn't been out in the rain, so it's probably not a leak from an exterior seal. He said that he checked under the dash by the pedals but didn't see any water coming from anywhere. The only explanation that I can think of would be condensation. He lives in Arkansas, so it gets pretty humid. Could using the air conditioner in a humid environment cause this to happen? I can't think of any other explanation. Does anyone know what may have caused this? Thanks in advance!