On chilly winter nights, sleeping under an electric blanket can be a much-needed reprieve from the frigid temps. It’s also a cozier and more cost-effective alternative than cranking up the thermostat. While electric blankets are generally considered safe for all-night use, here’s what to know to help ensure a good night’s sleep.

How Electric Blankets Affect Sleep

Keeping the bedroom on the cool side is considered most conducive for sleep, but the ideal temperature isn’t the same for everyone. Too hot, and we toss and turn; too cold, we shiver and likewise find it hard to drift off to sleep.

The general recommended room temperature range is between 60 and 67 degrees Fahrenheit, but a recent study found that older adults (over age 65) slept best when the range was even higher: 68 to 77 degrees Fahrenheit.

While electric blankets offer a cost-effective alternative to cranking the thermostat in the winter, keep in mind that being too warm may impede the natural temperature drop that occurs during sleep.

In general, “the quicker our body temperature falls, the quicker we fall asleep,” says Dr. Seema Khosla, medical director of the North Dakota Center for Sleep in Fargo.

Using your electric blanket all night long may also make it harder to stay asleep, given that excess heat reduces both Stage 3 (slow-wave) and REM (rapid eye movement) sleep. Additionally, if you find you’re restless because you’re feeling too hot, your sleep quality may be affected. Keep in mind, too, that if you’re using an electric blanket and also using a space heater or other form of ambient heating, the cumulative impact may affect your comfort (and, therefore, your sleep).

Finally, if you share a bed with someone else, you may find your partner’s predilection for a heated bed may be different than yours. “If you’re a hot sleeper, I think there’s a law that says you have to marry a cold sleeper,” Khosla jokes. (In this scenario, an electric blanket with dual controls may be useful.)

Other options include using an electric blanket as you’re preparing for bedtime, either as a way to heat up your bed ahead of time or to snuggle under while you’re on the couch watching television. “If you go into a cool bedroom after being warmed up with the blanket, your body temperature probably will fall faster,” Khosla explains. It’s the same principle behind taking a warm bath prior to bed; she notes that channeling heat away from the body’s core as part of the cooling-off process afterward helps facilitate this cool-down for sleep.

Are They Safe for Everyone?

Prolonged heat exposure from an electric blanket can be an issue for someone with an underlying condition that impedes their ability to detect excess heat. This includes people with diabetes (which can cause nerve damage in the hands or feet), those with other causes of poor circulation, and those with Alzheimer’s disease or other forms of dementia who may have reduced temperature sensitivity. Electric blankets also shouldn’t be used on infants or very young children, who are unable to indicate if they’re too hot (and for whom excess bedding is a risk in and of itself).

As with other electrical appliances used in the home, electric blankets are a source of low-frequency electric magnetic field (EMF) exposure. Because of this, several studies have looked at whether they increase the risk of various forms of cancers but haven’t found a link. One study, which included more than 87,000 women as part of the long-term Nurses’ Health Study, focused on invasive breast cancer; another, which included more than 89,000 women, similarly found no link between electric blanket use and the risk of thyroid cancer.

Before using an electric blanket during pregnancy, it’s best to consult with your medical provider, given the potential risk associated with excess heat.

And if you’re fond of cosleeping with your pet, it’s best to forego the electric blanket, given the difference in your body temperatures and the risk of your pet chewing on the electric cord.

How They Work

Inside an electric blanket’s fuzzy exterior is an embedded system of insulated heating wires. During the first 20 minutes, while the blanket is warming up, the surface temperature is allowed to reach up to 194 degrees Fahrenheit (90 degrees Celsius). Other than this warm-up period, however, the blanket’s surface shouldn’t exceed 149 degrees Fahrenheit (65 degrees Celsius) in what’s called its “steady-state condition,” says Joel Hawk, manager of principal engineers and subject-matter expert on electric blankets at UL Solutions, which developed the standards used for evaluating their safety.

“Once it gets to that 20-minute marker, it has to start gradually coming down,” he explains.

The blanket’s built-in temperature controls monitor for hot spots throughout the blanket while it’s in use. Hawk adds that it’s fine to use your electric blanket along with a comforter; the blankets are tested for this and for various other scenarios (including using them when folded) to ensure they don’t exceed the maximum allowed temperature.

How To Select a Heated Blanket

When purchasing an electric blanket, look for a label showing it’s been certified by an outside testing agency (such as UL or Intertek). If you’re not sure how old your blanket is, your best bet is to purchase a new one, given that the technology for monitoring hot spots has advanced considerably in the past 20 years or so.

You want a blanket that “complies with contemporary requirements,” says Hawk. “Don’t pass it down from generation to generation,” he says, “and don’t pick one up at a flea market.”

Having auto shutoff is a nice feature but not an essential one, he says, given that the safety standards were designed to account for continued use.

Guidelines for Use and Care

When you’re using your blanket, plug it directly into a wall outlet rather than an extension cord due to the potential increased risk of overheating. Other best practices include ensuring that the power cord doesn’t get trapped under the mattress or box spring and unplugging your blanket when it’s not in use.

You may be wondering: How do you clean a heated blanket? Hawk suggests following the manufacturer’s instructions. Although electric blankets generally can be machine washed and dried, “we don’t want you to put it in a dryer and set it on the highest temperature setting,” he says, in order to avoid potential damage.

At the end of the season, when you’re storing your blanket away, Hawk advises not wrapping the cord too tightly around it to avoid compressing the wires. If your blanket starts to show any signs of damage, such as exposed wiring, it’s time to stop using it, says Patty Davis, spokesperson for the Consumer Product Safety Commission.

Even if your electric blanket still appears to be in good shape, replacing it every 10 years or so will help ensure that it complies with current safety standards. If you’d rather bypass the electric option altogether, you might even consider switching to a weighted blanket instead, which can provide additional warmth along with other soothing benefits.