Whether reading in a backyard hammock or enjoying the sounds of a stream on a camping trip, I’d much rather be outdoors than anywhere else. But mosquitoes can quickly ruin any outside time, targeting even the smallest patch of uncovered skin.

Daniel Markowski, Ph.D., of the American Mosquito Control Association (AMCA), warns, “Mosquitoes are responsible for causing more human suffering than any other animal.” He suggests, “The best way to prevent mosquito bites while traveling, including in parks or other natural areas, is to use a personal repellent.”

There are plenty of options to ward off mosquitoes, like candles (which often don’t work well) or bug spray. Still, mosquitoes seem to find me no matter what. So, when a friend recommended the Thermacell MR450 portable mosquito repeller, I was eager to try it out.

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I Tried It

Thermacell MR450 Mosquito Repeller

30.598% OFF$27.99 at Amazon

Shop on Home Depot

$34.95 at REI

Pros:

  • Easy to use and portable
  • Creates a wide zone of protection
  • Scent-free and quiet operation
  • Rugged build for outdoor activities

Cons:

  • Requires frequent mat and fuel replacements for long usage
  • Initial cost might be higher compared to traditional repellents
  • Not as effective in high-wind areas or when moving

What is the Thermacell MR450 Mosquito Repeller?

Mosquitoes are more than just a nuisance—they can carry serious diseases like the West Nile Virus, the most common mosquito-borne illness in the U.S. In 2024, the Centers for Disease Control and Prevention (CDC) reported over 1,400 cases of the virus across the country. While that’s a small fraction of the population, it’s not something to take lightly. Beyond health risks, mosquito bites can ruin relaxing outdoor time.

That’s where Thermacell’s MR450 comes in. This portable, handheld device—about the size of a disposable water bottle—uses a CR2032 battery to expel mosquito repellent. It’s silent and odorless, and it takes just 10 to 15 minutes to reach its full coverage area. The device offers 12 hours of protection, with refillable cartridges for extended use.

Though designed for outdoor activities like camping, hiking, fishing and hunting, the MR450 works just as well on a porch or patio, making it a versatile tool for keeping mosquitoes at bay during any outdoor activity.

Thermacell MR450 Product Features

Once you understand the activation process, the Thermacell MR450 is easy to use. To start, insert a repellent mat, load the fuel cartridge, turn it on and press the start button twice or thrice (it won’t activate with a single push). After that, place it in a central spot and let it do its job.

Refueling follows the same process as activation. However, the mats last four hours each, while the fuel canister lasts 12 hours, meaning you’ll need to swap mats more often than the fuel cartridge.

The MR450 covers about 15 feet in all directions and works best when stationary. It has a belt clip for portability, but movement may affect performance. “Its effectiveness may vary depending on wind, airflow and local mosquito species,” notes Markowski.

The device operates almost silently and without odor, making it tricky to tell if it’s on. It’s durable enough for outdoor use, but keep it dry to avoid damage and maintain its mosquito-repelling power.

How We Tested It

I took the MR450 on a weekend camping trip with my family along the Conejos River in Colorado’s Rio Grande National Forest in June—prime mosquito season. After a short hike along the river, we returned to camp around 5 p.m. to prepare dinner, and the mosquitoes were already bothering us, so I fired up the Thermacell.

It was my first time using it, and in hindsight, I should have tested it beforehand. Setting it up was straightforward, but it took me a few minutes to figure out how to turn it on. The push-button ignition is easy, but there’s no clear indicator that the device is running—aside from a faint sound. Once it started, it took about 15 minutes to kick in. Patience is key here, or a more thorough reading of the instructions than I managed.

I eventually left it on the picnic table to do its thing. After about 15 minutes, the constant buzzing of mosquitoes around us stopped. It stayed that way as we prepared dinner, cleaned up and played card games. We stayed up later than usual, so I swapped the mat once before bed.

The 15-foot protection zone seemed accurate enough—while I didn’t measure it precisely, it covered the area with our stove, coolers and washing station. However, when I left that zone to use the restroom, the mosquitoes immediately found me until I returned. That’s the main drawback of the Thermacell—it’s only effective within its range, and moving outside that radius makes it less effective. But it’s compact enough to attach to a pack or slip into a pocket for portability. Wind can also impact its coverage in a single spot, but it sometimes helps keep the bugs at bay, too.

Why You Should Trust Us

Ryan Van Bibber is an award-winning editor and writer with over two decades of experience in DIY and product testing, a passion he developed from working alongside his father, a carpenter and general contractor. He also created the Family Handyman Approved product testing initiative and previously worked as an editor for Outside Magazine, contributing to his expertise in testing products like Thermacell’s MR450 mosquito repellent.

For this hands-on review, we also consulted Daniel Markowski, Ph.D. from the American Mosquito Control Association. He holds degrees from Memphis State University (B.S. in Biology) and the University of Rhode Island (M.S. in Zoology; Ph.D. in Biological Sciences). With over 25 years of experience, Markowski has directed pest and vector management programs nationwide.

Sean Tirman, Content Updates Editor at Family Handyman, updated and contributed research to this piece. Sean has written shopping guides since 2016 and is a former associate editor at Gear Patrol.

FAQ

How long does the protection last per cartridge and mat? 

The Thermacell MR450 includes one fuel cartridge and three repellent mats. Each fuel cartridge provides around 12 hours of protection, while a single repellent mat lasts for four hours, meaning you’ll go through three mats per cartridge before needing replacements.

Is the repellent safe for pets and children?

Yes, the Thermacell MR450’s mosquito repellent is safe for use around pets and children, as it does not contain DEET or other harmful chemicals.

Can I use it while walking, or does it need to remain stationary? 

Thermacell promotes the MR450 for mobile use, such as hiking. However, we found that its mosquito-repelling power is more effective when stationary, making it ideal for activities like sitting around a campfire or relaxing in the backyard.

What Other Reviewers/Experts Had to Say

Joel Mason, an avid hunter, outdoorsman, GearJunkie reviewer, and mosquito-hater, calls the Thermacell MR450 “[his] weapon of choice against these devilish creatures.”

“The Thermacell really works!” says Tom Rutchik, a verified purchaser on Amazon who gave the Thermacell MR450 a five-star review. “[It’s] a life saver [sic] if the mosquitoes are out!”

“This device works wonders,” says Sherry Fascia of the Thermacell MR450 in her five-star review. “It has allowed me to spend more time outside this summer than I have in years, and I am very grateful to all my friends who recommended it to me.”

“I hunt a lot of swampy areas, and these are an absolute must,” says Jason M in his verified five-star review on Amazon, calling the Thermacell MR450 “always needed.”

Product Comparison

Overall, the Thermacell MR450 is an effective solution for repelling mosquitoes outdoors. While it may not match the potency of direct bug-repellent sprays, it offers a solid alternative without the sticky, unpleasant residue on your skin. It’s also more effective than bug zappers, which don’t work well on biting insects like mosquitoes, and offers a better range than citronella candles.

It’s simple to operate once you get the hang of turning it on and replacing mats and fuel cartridges. However, the cost of regularly replacing these components can add up compared to cheaper options like bug spray or candles. For occasional outdoor activities—such as camping trips or picnics—the MR450 is a convenient and reliable option, though it may be less ideal for daily home use.

Final Verdict on Thermacell

Spray-on repellents remain the most effective way to keep mosquitoes at bay, but they have some drawbacks. These range from minor annoyances like sticky skin and unpleasant smells to more severe concerns, such as the potential risk of seizures (particularly with DEET-containing sprays). For situations where you’d rather avoid these issues or can’t use bug spray, a spatial repellent like the Thermacell is an excellent alternative—especially for relatively stationary activities like backyard dinners.

The Thermacell is ideal for backyard use (on the deck, around a campfire, or other outdoor gatherings) and, thanks to its portability, can be taken to various locations. Remember that you’ll need to bring replacement repellent cartridges to maintain its mosquito-repelling capabilities.

Where to Buy the Thermacell MR450 Mosquito Repellent

On Sale
Thermacell Mosquito Portable Repeller Via Homedepot.comVIA MERCHANT VIA MERCHANT

I Tried It

Thermacell MR450 Mosquito Repeller

30.598% OFF$27.99 at Amazon

Shop on Home Depot

$34.95 at REI

Thermacell MR450 mosquito repellers are available at most places that sell outdoor and backyard equipment, including big-box retailers. The full range of Thermacell products, including the MR450, is available on Amazon, Home Depot and REI, with prices ranging from $35 to $45.

Author
Ryan Van Bibber
A career journalist with almost two decades in the business, Ryan has a natural curiousity to learn how things work and how to make them work better. That spirit has guided his career and helped guide him through his own DIY journey as a homeowner.
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Ryan Van Bibber