Early Sunday morning, Americans say goodbye to daylight saving time — and hello to an extra hour’s sleep.

After we turn our clocks back one hour, the darkness comes earlier, the nights grow colder, and for a variety of reasons, the risk of residential fires increases.

State Fire Marshal Jerry Rosendahl reminds Minnesotans that when they roll back their clocks, it’s time for two other essential measures: Install fresh batteries in home smoke alarms, and replace alarms that are 10 years or older.

 “Smoke alarms are at work every minute of every day, and after several years, the sensors wear out,” Rosendahl said. “They should be replaced before you discover the hard way that they’re not working anymore.”

He reported that about 90 percent of American homes have smoke alarms, but about one-third of the alarms don’t work due to age, or dead or missing batteries.

 In 2007, 26 percent of Minnesota fire deaths took place in homes without working smoke alarms, and 53 percent occurred from November through February.

Most home fire fatalities happen during the night, when residents are asleep.  The average escape time in a residential fire is about two minutes, according to Rosendahl, and while many smoke detectors retail for less than $10, some people behave as if a home fire won’t happen to them.

“People have homeowner’s insurance to protect their finances, because they know that disaster could strike,” he said, “but they fail to invest minimal time and money to save their own lives. We need to change that behavior.”

 For the greatest protection, install a smoke alarm outside each bedroom and on every level of your home, and have an escape plan to follow if an alarm sounds. Test your alarms once a month to ensure that they’re working properly, and never “borrow” smoke alarm batteries for another use.

 For more information on residential smoke alarms, go to www.fire.state.mn.us and select “Home Fire Safety” from the left menu.