Gear Review: Keeping Mosquitoes At Bay With ThermaCELL

ThermaCELL units are a worthy tool in the fight against biting flies (David Shedd photo)

Much of our time in the outdoors is spent finding ways to outwit bugs. Blackflies, ticks, mosquitoes, and other little biters can make life miserable. But of all of them, mosquitoes are the most pervasive problem. Unlike blackflies,they’re awake during the day AND at night; unlike ticks, they can chase you down; they’re known disease carriers, and that high-pitched whine can drive you nuts. While clothing with Insect Shield and insect repellents, particularly with high concentrations of DEET, can keep them at bay, any other strategy that will help is welcome.

And that’s where ThermaCELL mosquito repellent units come in.  Conceptually, it’s pretty simple…soak a fiber pad in allethrin (a synthetic version of the stuff that Insect Shield uses), then put it on a warm plate powered by a butane cartridge. The heat releases the allethrin and makes it rise, causing it to spread throughout the local area.  Mosquitoes (and other biters, although skeeters are the main target) can’t stand the stuff and move out of range. Not only do you not get bitten, but the whine factor is removed. The US military approved the devices and uses them, so they SHOULD work; but do they?

We tried out two versions, a  Lantern ($32 retail) and an Appliance ($27).  No, we aren’t making these names up; they’re that simple. The Lantern is geared more toward use in your backyard or car camping; the Appliance toward backpacking, hunting, fishing, any situation where size and weight are factors.  Both operate in the same way; screw in the butane cartridge, open a pad and slide it on top of the plate, flip the “on” switch and listen for the hiss of butane, then hit the ignitor. Both have a little window that lets you see if it lit; if not, hit the ignitor a few times. We didn’t often need to snap it more than once or twice…ignition has been quick and reliable on both units. One concern was “how much is this stuff going to stink?”; but frankly, we never noticed any odor from more than a few inches away (and if you don’t have anything better to do than sit with your nose a few inches from the unit, you need to be hanging out in more interesting places).

The Lantern provides a comfortable glow over roughly the same area it protects (David Shedd photo)

The first test of the Lantern was on the back deck, where it was an immediate hit.  Well, not immediate, exactly; it takes a few minutes to warm up.  After some trial-and-error, we found that the best technique was to take it out, turn it on, give it about a half hour, and THEN go out; by then, the allethrin had spread through the area and the bugs were already at bay. Evenings outside became immediately more pleasant, and we spent more time sitting around after dinners, rather than heading inside as the mosquitoes became more insistent.  There was an obvious difference with the ThermaCELL lit; we tried turning it off, and after not too many minutes the number of mosquitoes around us soared.  Clearly, it works to repel mosquitoes, as claimed.

Perhaps the best synergy of the Lantern, though, is that it has an excellent LED light built in.  With two levels of brightness, it has a nice, even glow to it.  The synergy comes from the fact that while bugs are typically drawn to light, this one repels them; the allethrin comes from the top of the lantern.  Finally, a way to have light in the middle of the table, rather than way off to the side to keep the bloodsuckers away! We found that for group backpacking trips, it was worth taking along even with the extra bulk, as it did double duty as our main lantern, while making the campfire area more pleasant to sit around.  In fact, if the mosquitoes aren’t hanging around, you can simply use it as a lantern without turning on the allethrin unit, a nice bonus.

However, in the summer we often don’t carry a lantern, period. With the long days, we’re usually asleep before we need area lighting. So, the weight and bulk savings of the Appliance become more appealing.  At 7 ounces with a full cartridge versus 17 for the Lantern (with batteries), it’s a more palatable choice.  Function is the same; they use identical cartridges and mats.  Typically, we only needed one cartridge, as they last for about 12 hours.  Most trips, we were only sitting around in one spot for a few hours at a time, so a cartridge would last for 3-4 days. The mats are good for about 4 hours each, so we’d take a few, but they weigh virtually nothing…no hardship there!

It’s easy to tell when to replace a ThermaCELL pad; new is blue, old is…not so much (David Shedd photo)

Time for the “nothing’s perfect” section of the article.  We found a few things about the technology that can be irritating.  The first one is fairly obvious…when it’s windy, it doesn’t work.  Get strong enough winds, and they blow the bugs away, but a moderate breeze is enough to blow away the allethrin but not the mosquitoes.  The second is related; while the literature states that it protects a 15’x15′ area, it doesn’t say WHAT 15’x15′ area. Think of the protection zone as a helium filled balloon; tether it to your neck and it sits directly over your head. But add a light puff of wind and it moves to the side. With the ThermaCELL, you can’t see the “balloon”, but you’d better be aware of its positioning. If there’s a light breeze from one side, put the appliance to that side of you. That increases effectiveness dramatically. But, if the wind direction is shifting around, you’ll find the protection comes and goes. The third and final problem is that heated allethrin rises, meaning that the biters can come in from underneath and harass your feet and ankles.  A pair of Insect Shield socks or a little DEET sprayed on your boots and ankles can solve that problem, but be prepared for it.

Availability of the units and refills is widespread; Wal-Mart, Home Depot, and many other stores carry them, or they can be purchased from ThermaCELL online.  Bottom line:  The ThermaCELL is a worthy weapon in your anti-bug arsenal.  Use it along with other measures, and it can make sitting around and talking (one of the best parts of camping!), dramatically more comfortable and pleasurable.  It’ll be in our backpacks this summer…


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