You can't count on your nose to warn you, but when your nose does warn you it pays to heed that warning. If your nose is screaming at you to GTFO, listen to it.
You listen to your other senses, right? When you touch something hot, you listen to your sense of touch telling you that you're about to get burned. That doesn't mean your sense of touch can warn you of all hazards, but you certainly shouldn't ignore it when it does.
