There's only one place you should even consider barbecuing, and that's outside, away from any buildings. That includes tents and garages. Porches and decks, especially on older homes and multi-family buildings, also pose a fire danger. Twenty-nine percent of home fires involving grills between 2005 and 2009 started on a courtyard, terrace or patio, and 28 percent started on an exterior balcony or open porch [source: NFPA].
In Manchester, N.H., which has a large immigrant population, there have been reports of people using antique cast-iron bathtubs to grill, says Balch. That can create a smoke-inhalation risk by itself, but can be worse when they suggest that friends with Fiberglas bathtubs try the same thing. But even people cooking on small, propane-fueled grills indoors pose an enormous health hazard if the fumes aren't vented outside.
"Carbon monoxide tricks the hemoglobin in the blood so quickly," says Balch. "The hemoglobin likes the carbon monoxide a thousand times more than it likes oxygen. So if you get a big lungful of carbon monoxide, your hemoglobin will grab onto that carbon monoxide and won't let go of it. Now your hemoglobin is full of carbon monoxide, and you asphyxiate yourself because you can't get any oxygen to attach to your blood."
Even more staggering is the miniscule amounts of CO that can prove fatal. "It doesn't take much before you get sick -- 3,000 parts per million," says Balch. "At 16,000 parts per million, you're dead in three minutes. It's very, very toxic. Carbon monoxide is the silent killer.
"You have so many petroleum products in your house -- the couch, the carpet, the curtains -- everything has gas in it," says Balch. "That black smoke with the curly Q's in it? One big sniff of that, you'll pass out and you'll lie there and breathe that, saturating your body. You'll be dead long before the fire kills you. It only takes three minutes, and you're out."
Lesson learned? If Mother Nature puts a damper on your grilling plans, put them aside for another day.