I think the idea is that it's what you might imagine as your worst nightmare. I didn't have anything in mind when I started writing, just when the timer went off, it felt... like a terrifying place. Whether that's a mental hospital, some whacked out lunatic's experimental hospital, some creep's basement or a black site interrogation room like @jaichai suggested... who knows?
Long story short, No clues. I rarely ever think things out that far, but that would be cool to do! :)