We all go to sleep at night, but each year 170 of us never wake up thanks to this silent killer. The culprit: carbon monoxide poisoning caused by malfunctioning fuel burning appliances such as furnaces, ranges, water and room heaters. One way to protect yourself is to make sure you vent the exhaust of these appliances properly. That means having the pipes angle up, not down, as these folks have done—hot air rises, you know—and checking that vents are free of cracks and gaps. And most importantly: install a standard carbon monoxide detector. They only cost 20 bucks and are the best way to protect your family.