Your Garage Needs a Heat-Sensing Fire Alarm

Why a smoke detector may not be enough to protect you and your family

By Benjamin Preston

November 5, 2024

SUV cars parked in an attached home garage

Having a fire alarm in your garage is important, especially if your home has an attached garage or a garage near rooms where people sleep.

Fires can spread quickly, and by the time a garage fire starts to consume a home, it poses a serious threat to both life and property. But a typical smoke alarm won’t work well enough for your garage. You need a heat detector.

Smoke alarms are great protectors in the house, but in the garage, tailpipe fumes or dust blown in through a large garage door opening are likely to set off false alarms. The solution is a heat alarm, a small device that sounds an alert when high temperatures are measured. According to the U.S. Fire Administration, installing a heat alarm in your garage is a good way to keep yourself safe without causing the false alarms you’re likely to get with a smoke or carbon monoxide detector.

“Car fires are relatively rare, but they do happen and lead to quite a few recalls every year,” says Gabe Shenhar, associate director of Consumer Reports’ Auto Test Center. “So even though most cars are safe, the potential is there, so a little bit of precaution is a good idea.”

More than 150,000 Jeep plug-in hybrids were recalled for fire risk in October 2024, and more than 40,000 Ford SUVs were recalled earlier this year. Over the past 12 years, more than 10 million fire-prone Hyundai and Kia vehicles have been recalled. According to the National Highway Traffic Safety Administration, more than 3,100 of those vehicles have actually caught fire since 2010.

When you compare those numbers to the hundreds of millions of registered motor vehicles in the U.S.—Consumer Affairs says there were more than 283 million in 2023—a few thousand here and there doesn’t sound like many—until it happens to you. If the worst happens, you want to be prepared with a heat-detecting alarm. Preferably, you’ll have one that is connected to other alarms in your house or can send an alert to your phone.

The number of fires in the U.S. has fallen by 50 percent since 1980. Still, there were 3,790 deaths and 13,250 injuries associated with fires in the U.S. in 2022, the last year for which data is available, according to the National Fire Protection Association, a nonprofit that writes fire safety codes. Roughly three-quarters of those deaths and injuries happened in peoples’ homes, highlighting the need for reliable and redundant fire detection devices and fire extinguishers.

Types of Fire Alarms

The NFPA says that there should be smoke alarms on every floor of a residence—both inside and outside sleeping rooms, and at both ends of hallways longer than 40 feet. (Note: Your home should also have a fire extinguisher on every floor, as well as in kitchens and garages.) Newer homes and homes that have been renovated now have hardwired, interconnected alarm systems that will set off all the alarm modules if one of them detects smoke or carbon monoxide. These are often part of comprehensive home security systems. For older homes that don’t have special fire alarm wiring, Bluetooth-enabled alarms are available to perform this function wirelessly. And many new alarms feature apps that will notify your phone if an alarm is activated.

Which kind of alarm do you need? It depends on where you’re putting it. Read on to learn more about the various types.

Smoke Detectors
These can be hardwired, battery-operated, or powered by electricity from an outlet (with a battery backup in case of a power failure). Some battery-operated units come with lithium batteries that last up to 10 years, while others contain traditional AAA, AA, and 9-volt batteries that should be checked or replaced annually.

According to NFPA, most fire deaths are caused by inhalation of smoke, which usually contains the toxic combustion byproducts from burning plastics, foams, and other common synthetic household materials.

Because smoke rises with heat, smoke detectors should be placed near the ceiling to ensure early detection. The best place to put smoke detectors is in sleeping rooms, hallways, and near the kitchen (at least 10 feet from the stove, where cooking can cause constant false alarms). Check Consumer Reports’ ratings of the best smoke detectors.

What to Do If Your Car Catches Fire

CR shares these steps to prevent a car fire and, if necessary, deal with a fire.

Carbon Monoxide Detectors

Carbon monoxide is an odorless, colorless gas that is slightly lighter than room air, meaning it tends to rise. It can accumulate in indoor spaces if there’s a gas leak, or if a furnace, boiler, or water heater is malfunctioning. According to the Centers for Disease Control and Prevention, more than 400 Americans die from accidental CO poisoning every year and more than 100,000 require emergency care.

Like smoke detectors, CO alarms come in the hardwired, battery-operated, or plug-in varieties. NFPA recommends installing CO detectors on every level of your home, outside sleeping areas, and outside attached garages, where a car may have been inadvertently left running. (Note: Driving the car in and out of an attached garage on a regular basis should not set off CO alarms mounted inside the house. But this is protection against a car being left running in a closed garage.) Look over CR’s reviews and ratings for the best CO detectors. CR also tests combination smoke/CO alarms.

Heat Detectors

These devices work where smoke detectors can be problematic, such as areas where dust, humidity, and steam are often present. This is why you don’t often see smoke detectors in bathrooms. Heat detectors do exactly what the name implies: They sound an alarm when a high temperature indicates that a fire has started, either at a set temperature threshold, or when the temperature rises quickly enough to indicate that a fire has started. They’re ideal in garages, where dust, humidity, car exhaust fumes, and even insects can cause false alarms in a smoke detector.

The U.S. Fire Administration advises installing a garage heat alarm that’s interconnected with the other fire alarms in your home, with a temperature rating between 175° F and 200° F. (The temperature inside an unconditioned garage can exceed 100° F in summer, but sunlight alone won’t cause the temperature to rise enough to trigger the alarm.) The agency also advises mounting these devices away from fluorescent lights, which can impact their operation.

A number of models are available, including both standalone units and interconnected models that work through a smartphone app with a wireless base station. (CR hasn’t tested heat detectors.)

Interconnected heat alarms are your best option, as they will set off other smoke and CO alarms in your house if there’s a fire in the garage, giving you more time to call 911 and get to safety.

There are also hardwired heat detectors (equipped with battery backup) that are usually installed in newer construction and renovations, but they may be more difficult to install in an existing structure.

Benjamin Preston

Benjamin Preston covered new and used car buying, auto insurance, car maintenance and repair, and electric bikes for Consumer Reports.