ThermaCell ProFlex Heated Insoles Review

ThermaCell ProFlex Heated Insoles

Although I’d never tell my first- or fourth-grader, sometimes two plus two doesn’t equal four. A product can have outstanding technical specs and potential and yet not equate to a great finished product. When you’re hiking outdoors with Raynaud’s syndrome, it’s important to keep your cold-sensitive feet warm because you can’t just turn around and hop immediately back into the car or house to heat up. I was excited to learn about the ThermaCell ProFlex heated insoles, because on paper they offer a great solution to this issue. But in practice, they simply don’t deliver.

The technical specs of the ThermaCell ProFlex heated insoles paint a great picture: two different heat settings (Medium and High), a wireless remote, a removable battery for recharging without removing the insole itself, and a flexible construction that bends with your foot. On paper, there’s nothing the ProFlex insoles are missing. But I, like most people, don’t hike on paper. And the real world is where they fall short.

Getting the ProFlex heated insoles ready for use outside is a breeze. The package includes a small battery-charging dock, a USB cable and a USB-to-outlet adapter, and it’s intuitive to plug everything in and get the process going. Both batteries come with a slight charge, so it took just two hours to charge them the first time. After that it took three to four hours to charge, which gets you that same amount of usage time on the High setting and up to five hours on Medium.

Whereas the company’s original heated insole was rigid, the ThermaCell ProFlex heated insoles are aptly named. As you can see in the video below, they bend and flex from mid-foot to toe, mimicking the bending of your foot as you walk. They’re still thick, so you’ll need to remove your shoes’ or boots’ native insole before installing this, but that’s to be expected. The removable battery also has some cushion to it, so it never feels like there’s a small brick underneath your heel. Obviously this makes walking in them much more comfortable.

Unfortunately, that’s where the comfort stops. Getting the insoles to actually heat-up takes much longer than I expected. I didn’t notice a modicum of heat until 15 minutes after I’d turned them on High, and it took even longer on Medium. After 30 minutes the insoles seem to attain their maximum temperature, but even then they didn’t add any more heat than just wearing heavyweight socks. I wish that were an exaggeration, but it’s not. The heating wires are also only in the toe area with nothing in the arch or heel. The heel part’s understandable, since that’s where the battery is. But the arch is a big miss. Or more accurately, it would’ve been a miss if these insoles had generated any notable heat. ThermaCell says the insoles keep your feet “warm without getting them too hot and making them sweat.” Let me assure you, overheating your sensitive cold feet is never an issue with these.

The ThermaCell ProFlex heated insoles also suffer from major outgassing. Upon opening the box I was hit with an immediate chemical stink that didn’t dissipate through two weeks of occasional use. It got to the point that I removed the insoles after each use in an attempt to keep my shoes from permanently smelling the same way. As it was, the insoles made my shoes smell like chemicals after being inserted for just 30 minutes, and it took two hours for the stink to go away. Having to remove the insoles due to their odor completely nullifies the concept of having removable batteries.

I was quite eager to test these heated insoles, and I wanted desperately for them to perform as billed. But they didn’t. Not even close. It’s completely possible that I got a lemon; that happened in one of my Xtreme Canteen reviews. But if this is the standard performance, I would not recommend these ProFlex insoles. You’d be much better off investing that $185 in a pair of insulated hiking boots that’ll keep your feet from getting cold in the first place.

The ThermaCell ProFlex heated insoles were provided for review. All opinions and words are my own and honest, and the article contains no affiliate links.

ThermaCell ProFlex Heated Insoles

ThermaCell ProFlex Heated Insoles


9.0 /10


3.0 /10


7.5 /10


4.0 /10


  • Great cut-to-fit options for different shoe sizes
  • Super flexibility bends with your foot
  • Cushioned battery pack feels comfy under the heel
  • Removable batteries for recharging


  • They give off hardly any heat
  • Horrible chemical stink / outgassing
  • Price is high considering their performance

Jonas Allen

Jonas spent 17 years covering travel, technology and entertainment for regional and international media. He now writes about gear, clothes and tips to stay warm. He hopes his lessons will help other people who get cold (re)discover the great outdoors.

3 thoughts on “ThermaCell ProFlex Heated Insoles Review

  • November 13, 2017 at 9:01 am

    I bought mine 2 years ago
    Noted the same thing as in the review.
    Furthermore, I tryed them this year and only one of the soles appears to be working
    Called customer service to try to guess what was wrong (maybe pairing with the remote). They keep referring to a light on the battery that I could not see.
    I gave up
    Won’t be buying new ones…

  • September 30, 2018 at 3:43 pm

    This has to be the worst product ever. Purchased the heated insoles and extra batteries and they never warmed up. Contacted customer service 4 times. They responded to my first emailed requesting product and model number information. Never heard back from them since. Do NOT waste your money!!!

  • December 2, 2019 at 4:42 pm

    Dont do it , second pair and same story, one foot does not work and cant find any help.


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