This Thermacell mosquito repellent is a game-changer for outdoor gatherings — and it's 25% off for Prime Day

When you buy through our links, Business Insider may earn an affiliate commission. Learn more

There always seems to be one person at the party who mosquitoes bite more than anyone else, and unfortunately, that person tends to be me. I'm a magnet for mosquitoes, which makes spending time outdoors in the summer a less-than-pleasant experience. Not only do mosquito bites itch terribly, but the insects can carry harmful diseases like the Zika and West Nile viruses, so I typically slather myself in sticky bug spray before any outdoor event. 

It would be nice to sit outside without spraying chemicals all over my body, which is why I started looking for a mosquito repellent to use in my outdoor living space. In particular, the Thermacell E55 Rechargeable Mosquito Repellent caught my eye, as it's designed to create a 20-foot zone of protection against mosquitoes without having to put any spray or lotion on your skin. I tried out this mosquito repeller for several days, and it's officially going to be my go-to option for preventing itchy bites. 

If you're looking for a way to keep mosquitoes at bay this summer, the Thermacell E55 is on sale for 25% during Amazon Prime Day, so now's the perfect time to pick one up. Here's what it's like to use and everything you should know before you buy one for yourself. 

It's easy to set up and highly portable

When I unboxed the Thermacell E55, I was surprised at its small, lightweight form. It's roughly the size and shape of a stemless wine glass, and it weighs just a few ounces, making it easy to carry around. 

Before using it, I charged it for a few hours using the included USB cord and then inserted the 12-hour cartridge that comes with your purchase. The cartridge pops into the base easily, and the whole thing takes just a few seconds to set up. 

During testing, I particularly loved the E55's wireless, portable design. Because it runs on a rechargeable battery, it can be used anywhere, and its lightweight design makes it easy to move around. In addition to using it on my own patio, I often brought it with me to my parent's house, where we occasionally have dinner out on the deck. It's a breeze to transport, and the cartridge doesn't even leak if you tip it over. Because it's so compact, I can see it being useful for camping, picnics, or tailgating.

It keeps away mosquitoes without any odors or sprays

I tested the Thermacell E55 for several days during the summer in New England, and I was really impressed at its ability to keep mosquitoes at bay. The design is quite simple: The base heats the repellent cartridge, which is filled with a 5.5% Metofluthrin solution — an insect repellent that's especially effective against mosquitoes. The heat turns the liquid into a vapor, which is diffused out the top of the device, and the vapor knocks down and kills mosquitoes when they come in contact with it. 

When I used it, the Thermacell generally took around 5 minutes to heat up — the lights on the front of the device switched from a "chasing" pattern to a solid state when the device was fully armed. True to claim, the repeller was completely silent and didn't emit any noticeable odors or mist, yet it was impressively effective. On three different nights, I sat outside for more than an hour with the repeller, and I didn't get a single mosquito bite. It worked so well that I thought it might be a fluke, but when I walked out into my backyard, out of range of the repeller, I got bitten by a mosquito almost immediately. 

It's hard to gauge exactly how big of a protective bubble the Thermacell creates, but it was definitely powerful enough to provide protection for our outdoor dining table with several people seated around it. The closer you are to the device, the more effective it will be, so it's best to keep it situated in the center of the area that you want protected. 

The repellent lasts for hours

I was able to use the Thermacell E55 for several days before needing to recharge the battery. This model can run for around 5.5 hours per charge, making it well-suited for outdoor meals or relaxing outside with guests. If you want an even longer-lasting option, the Thermacell e90 is the same design but with a longer battery life of nine hours. When the battery runs out, the device is easy to charge. Just plug it in for a few hours, and it's ready to go. 

Eventually, the device will also run out of repellent, but the cartridges are quick and easy to replace. The base comes with a sample 12-hour cartridge, and you can purchase larger replacement cartridges that offer 40 hours of protection each. 

Cons to Consider

Overall, I was really impressed by Thermacell E55, but there are a few caveats to keep in mind before you buy. Because the device works by releasing a vapor into the air, the repeller isn't as effective on windy days, as the vapor will get blown away more quickly. The brand suggests sitting down-wind of the device for best results. Additionally, Metofluthrin is really only effective on mosquitoes, so it won't protect you against other biting bugs. 

I was also a bit surprised at the cost of the replacement cartridges. A single 40-hour cartridge costs around $20, and a four-pack is $55. If you use the repeller frequently or for long periods of time, these costs could add up pretty quickly. 

The Bottom Line

If you're looking for a way to repel mosquitoes without lathering up in bug spray, the Thermacell E55 Rechargeable Mosquito Repellent is a worthwhile investment for your outdoor living space. It's totally silent and odor-free — you can barely tell that it's even on. Yet, it's highly effective at keeping mosquitoes away as you relax outdoors. Plus, its compact and portable design makes it a great option for camping, tailgating, and other outdoor events, allowing you to enjoy the weather without worrying about itchy bites.