When the weather outside is frightful, losing your heat or electricity is the last thing you want to have happened. But don’t let your fear of such an event push you into falling for a common scam perpetrated by fraudsters trying to pass themselves off as utility company employees on the phone.

We’ve seen these scams at work in the past, whether it’s an electric company impostor or a gas utility poseur. Though some scammers will call up and demand immediate payment for unpaid utility bills, others will cold call folks and ask for personal and billing information, telling them they’re eligible for a federal program or will offer to lower a utility bill. Once the fraudster has that information, they can steal your identity.

It’s especially important to remain vigilant as these scam calls are on the rise, according to an analysis of 3.5 billion monthly calls and texts from a spam protection service called Hiya (via MarketWatch).

Utility-related scam phone calls went up by 109% in 2016 and will likely continue to rise as scammers get more creative in trying to fool a savvier public, Hiya says. The top five companies scammers pretend to be from General Electric, Duke Energy, ConEd, Georgia Power, and Consumers Energy. The most common area codes for these scam calls are 508 (Massachusetts), 201 (Hudson, NJ), 914 (Westchester County, NY), 323 (Los Angeles), and 330 (Akron, OH).

Both the Federal Communications Commission and Federal Trade Commission have warned consumers about these kinds of scams in the past, urging them to immediately hang up if they aren’t sure the call is legitimate, and call the utility company back using their listed phone number.

You should also report the incident to your real utility company, the police, the FTC’s Complaint Assistant, and to the FCC’s Consumer Help Center.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.