[eru]

Open the window or run the aircon.

[gpm]

This is a hotel room, you would need the last hundred guests to have done that, not yourself

[godelski]

Considering this and your other comments I really think you need to think a bit deeper about your answers. I believe in you, just ask "and then what happens" and I'm positive you'll figure it out.

[eru]

I've both opened windows and ran aircons. (Though I try to avoid doing both at the same time.)

Nothing bad happened.

[godelski]

  > Nothing bad happened.

Keep at it, you're almost there. You just forgot about one important variable: time

[eru]

If done both for a long time over many years.