Summer mosquitoes repelled by ThermaCELL

Bill Schawbel showed off two of his ThermaCELL products, which radiate bug repellant.
Jessica Rinaldi for The Boston Globe
Bill Schawbel showed off two of his ThermaCELL products, which radiate bug repellant.

BEDFORD — Bill Schawbel loves mosquitoes. For real. This is a direct quote: “I love mosquitoes.”

He’s telling the truth. And for two very good reasons, which may be the only two reasons any sane person can believably say that they love mosquitoes: 1) He has devised a way to keep mosquitoes away. 2) That idea is making him a lot of money. His company just had the two best weeks in its history.

Schawbel’s device claims to create an invisible 15-by-15-foot bubble around itself that repels mosquitoes, black flies, and no-see-ums. If that sounds too good to be true — and Schawbel readily acknowledges that the entire idea sounds gimmicky — let’s throw in another interesting detail: Schawbel’s recent status as a mosquito’s worst friend is basically an accident.


Bill Schawbel is a lot of things. His resume is obnoxiously accomplished. But mosquito scientist isn’t on it. He’s 73, originally from Roxbury, and has been a well-known entrepreneur and philanthropist in Boston for decades. He’s on the boards of 30 nonprofits, donates more than half his salary and 10 percent of the company’s profits to charities, and, as septuagenarians go, he’s definitely on the hyperactive side. In the past two months, he’s traveled to eight countries, and he is training to run next year’s Boston Marathon, just as he did when he was 70.

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But while he’s not an entomologist, what he does know is heat, and he owns the patents for a very specific way of creating portable heat using small butane cartridges. “Think of it as a gas battery,” he says; hence the device’s name, ThermaCELL.

For a while, Schawbel used the portable heat technology — which he acquired when he bought two divisions from Gillette in 1981 — to do rather mundane things. First, his company created a line of portable, cordless hair straighteners and curling irons; later on, they moved into portable soldering irons and glue guns.

Then in the ’90s, he was approached by a big player in the insect repellent game — Schawbel declines to say who — with the idea of using this portable heat to create a device that would disperse insect repellent. When Schawbel was unable to create the devices for less than $10 as the partner wanted — they retail for between $20 and $30 — the other company backed out and Schawbel continued on his own.

The device uses a cartridge of butane, the fuel used in portable lighters, to heat a metal grill that, in turn, heats a small fabric strip saturated in allethrin, a synthetic form of a chemical found in the chrysanthemum flower.


Once it’s going and has had 15-20 minutes to create a cloud of allethrin, the company claims, the device will repel up to 97 percent of mosquitoes and 79 percent of those horrific black flies.

Among the first good customers for the original device, about the size of a first-generation cell phone, was the military, which used it extensively in Iraq and Afghanistan to combat sand fleas. Then hunters picked it up, Schawbel said, including many who had discovered the product in the service.

“I absolutely will not go into the woods without it,” said Sean Callanan, a professional hunter from Middleton who is not affiliated with the company. Callanan said he first learned of the product a decade ago on a bear hunt with his father deep in the Canadian wilderness. His dad was skeptical, so they started the hunt in a full bug suit and it was awful, with bugs swarming their faces. Then they fired up the ThermaCELL. “My dad’s an old Marine, and he thinks everything is a gimmick until it proves itself,” Callanan said. “After 20 minutes, he said we could now hunt in Speedos if we wanted to.”

On a forum, one person said the ThermaCELL was the best thing to happen to hunting since the bow and arrow; another said it was the best thing since free beer. Field & Stream gave the product its “Best of the Best” award. Outdoor Life magazine simply called it “the best invention of the 21st century.”

Schawbel loves the praise from the hunters. They’re a no-gimmick crowd, and their word-of-mouth is what built the brand. But hunters and campers are just one market. The backyard and patio market is much larger, and Schawbel is now trying to make a push there, expanding beyond the original handheld device into a line of ThermaCELL patio lanterns that are now on the shelves of big-box retailers such as Target, Walmart, and Home Depot. Business has boomed this summer, Schawbel said, and after a recent 30-second segment about the product on Good Morning America, they received nearly 15,000 orders on their website in one day. People hate mosquitoes; everyone, it seems, except Bill Schawbel.


While some have raised concerns about the use of the insecticide allethrin — Schawbel stresses the product has been approved by the EPA — the biggest complaint against ThermaCELL is its cost. The devices come with one butane cartridge, which lasts up to 12 hours, and three repellent strips, which must be changed every four hours. After that first 12 hours, you have to buy refills for each from ThermaCELL, at a cost that works out to about 50 cents for each hour of use.

“It’s a blade-and-razor business,” Schawbel said, something he learned at Gillette. “It’s simple: If you satisfy a customer, you have a customer forever.”

Recently, as Schawbel prepared to go for a walk on a wooded trail near his office in Bedford, he reached down and fired up the ThermaCELL, and his face lit up as he heard the familiar whoosh of butane lighting.

And that was it. The magic had, allegedly, started.

As he led a reporter into what is normally a very buggy stretch of woods, his excitement melted a bit. It was the middle of the day and blazing hot. There were no mosquitoes to be found. Bill Schawbel was disappointed. The guy loves mosquitoes. He really does.

Billy Baker can be reached at Follow him on Twitter @billy_baker.