Thermacell Patio Shield Halo Mosquito Repeller

Thermacell Patio Shield Halo Mosquito Repeller
PTR Review
  • Pro Review 9.3

Without the use of spray-on repellents or chemicals that kill insects indiscriminately, I wasn't bitten by a mosquito once while I used the Thermacell Halo. Not once - in late spring - in Florida. It's remarkable.

Overall Score 9.3 (out of 10)

Nothing kills a good outdoor vibe like the buzzing and bites of just one little mosquito. A lot of us use the first bite as an indication that it’s time to go inside. By that standard, you probably won’t spend much time outside at all. You could spray on some DEET repellent. While it works, some people have safety concerns about its use even if they don’t have any adverse reaction to it. It makes me sneeze about six times in rapid succession right after I spray it on, which I always find to be a small price to pay to avoid annoying sounds and itches. But does the Thermacell Patio Shield Halo Mosquito Repeller change things?

I picked up a Thermacell mosquito repeller a couple of years ago after reading several outdoorsmen’s rave reviews about it – and I found they were right. I’ve also tried out the Thermacell Halo Backpacker and Tick Control System. So I have high hopes for the new Thermacell Halo, which uses the same mechanism and includes a few cool features. Bring it on, skeeters!

First Impressions

The Halo is a sleekly designed cylinder whose purpose you probably couldn’t identify if you didn’t already know about it. If you’re unfamiliar with Thermacell’s technology, here’s a quick synopsis: liquid butane ignites inside the device (there’s no open flame) and heats up a blue mat containing allethrin.

At a certain temperature, the allethrin releases from the mat into the air, producing a smell that’s barely noticeable to us but that mosquitoes apparently find repugnant. This creates a zone of skeeter-free protection.  Thermacell’s older products only have a small viewing window that glows orange with the internal heat and indicates the butane is burning. The Halo includes that but it also has an optional feature that Thermacell calls the ZoneCheck Monitor which indicates when the heating area is warming up and when it has reached a temperature that releases the allethrin.

Thermacell Patio Shield Halo Mosquito Repeller

More on that in a minute.

There’s only one way to find out if it works – offer up my own blood as a potential mosquito feast and see if anyone shows up for dinner.

Halo and Goodbye Mosquitoes!

Thermacell Patio Shield Halo Mosquito Repeller Design

The Thermacell Patio Shield Halo Mosquito Repeller cylinder has a cap on the top and bottom. The top cap is simply protective when the Thermacell isn’t in use. It covers the heating area and honeycomb plastic grate that holds the blue allethrin mat found inside the small, foil package that comes with the Halo. The mat slides between the honeycomb and heating area, sandwiching securely until it’s time to change it (about 8 – 9 hours).

Thermacell Patio Shield Halo Mosquito Repeller

The bottom cap pops off of the cylinder to reveal ports for up to four liquid butane fuel cartridges and spots for four AA batteries. You can install as few as one butane cartridge – they burn in sequence so more cartridges don’t increase the amount of allethrin released or the size of the protection zone. Each cartridge just increases the runtime, which is about 12 hours each.  The batteries aren’t necessary for the repellent release. Rather, they power the ZoneCheck Monitor. If you don’t have batteries or they die, the Halo can still protect you from those little flying vampires.

I replaced the bottom cap after I installed the butane cartridges and batteries. I hoped that I was just moments away from outdoor bliss.


The Halo has a white ring with a tab around the middle of its body. This is both the ignition system and ZoneCheck Monitor. The ignition of my smaller Thermacell is simple. You simply turn the switch to ON, press the button, and “click!”—we have ignition.

The Halo’s ignition is different but equally as simple. I pushed the tab to the ON position and heard a slight puff as the pressure on the butane cartridge was released. After 3-4 seconds, I pushed the tab once more to the right and heard the same click. It’s not unlike lighting a grill without the open flame (or burgers).

Thermacell Patio Shield Halo Mosquito Repeller

I peeked inside the viewing window and saw the familiar orange glow. But that doesn’t mean mosquitoes instantly high-tail it out of the area. The Halo has to heat the allethrin mat to the right temperature to release the repellent first. And that’s where the ZoneCheck comes in so handy. Once ignited, but before the optimum temperature is reached, ZoneCheck emits a pulsing light in the Halo’s white ring. Once it reaches active repelling temperature, the pulse turns to a solid glow.

This clever indicator might be most helpful when your butane supply is running low – the temperature naturally decreases and the pulsing light will begin again.

Tossing a Soft Pitch

Central Florida experiences its share of severe droughts. Even that doesn’t seem to slow down the mosquitoes. At first, I threw the Halo a couple of softballs. I fired it up, let ZoneCheck tell me it was ready, and placed it on the floor near the open door of my workshop. The airborne monsters invariably find their way to my ankles and legs when I do this, but I didn’t feel the first bite.

I sat outside in the morning and drank some coffee. No bites.

Throwing a Fastball

Then I turned up the heat, so to speak. Along the side of my house, there’s an old tire that I keep forgetting to put out with the trash every week… for a few years now. You’d think I’d write myself a note. Anyway, if you want to attract mosquitoes to your place, have an old tire along the side of your house with a little standing rainwater at the bottom. It’s a breeding ground.

Thermacell Patio Shield Halo Mosquito Repeller

I put the Halo down beside the tire and waited just a couple of minutes. I bravely wore shorts and sandals and gave the tire a good kick. Out flew about six of them and I waited for the bites. Nothing. I kicked it again and let a few more minutes pass. Not the first bite.

Throughout the rest of the review on the Thermacell Patio Shield Halo Mosquito Repeller, I found that I couldn’t make a mosquito bite me when the Halo was nearby. It was remarkable. I might be the first Floridian in history to not donate blood to one of these terrible little devils in April and May.

As we’ve talked about in the past, the only potential drawback to this repellent method is a windy day, but then again, the wind blows away the mosquitoes with it.

The Bottom Line

If you want to enjoy your time outside without being attacked by mosquitoes, there might not be a better overall method than using the Thermacell Halo. There are no chemicals to put on your body that might cause adverse reactions or, at the very least, leave a strange odor on your clothes. If you’d like to have your whole yard sprayed with repellent but are concerned, like I am, about detrimental effects on pollinators, you can use the Halo without worry.

Throughout the review, I wasn’t bitten by one mosquito despite putting myself in harm’s way for long periods of time. I can’t underscore its effectiveness enough, so now I’m sure to bring the Thermacell Patio Shield Halo Mosquito Repeller, some allethrin mats, and butane cartridges with me just about everywhere I go. At just $39.99 for everything you need for hours of bite-free outdoor time, it’s hard to go wrong.

Thermacell Patio Shield Halo Mosquito Repeller Features

  • 225 Square Foot Protection Zone
  • Repels Mosquitoes That May Carry Zika and West Nile Virus
  • Accepts Up To 4 Fuel Cartridges for 48 Hour Fuel Runtime
  • ZoneCheck Monitor Shows Halo Is Activated
  • Weather-Resistant Design and Cover Protect the Repeller from the Elements When Not in Use
  • Compatible with Thermacell 4 and 12-Hour Mosquito Repellent Mats
  • Silent and Scent-Free
  • Price: $50

Thermacell Patio Shield Halo Mosquito Repeller Specifications

  • Butane Cartridge Volume: 0.41 ounces
  • Repellent Mat Ingredients: 21.97% d-cis/trans allethrin, 78.03% inactive other
  • ZoneCheck Power: 4 AA Batteries (not included)

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