ThermaCELL Heated Insoles Review (Bluetooth Foot Warmers)

This product review is looking at the heavy duty ProFLEX heated insoles with Bluetooth by ThermaCELL.

These insoles are battery powered and controlled via Bluetooth from your Android or Apple device.

Thermacell heated insoles Bluetooth

They’re supposed to keep your feet warm for up to eight and a half hours and recharge in less than two.

Let me break this review down. The first thing we’re going to do is unbox it, take a closer look at it, then I’m going to show you how to download the free app, how to use it, I’m going to test out the battery life, we’re going to test out max temperature and then I’m going to tell you how my own field testing went and then after that we’re going to wrap it up with pros and cons, where to get it and how much it cost.

These heated insoles are wireless and rechargeable. These are the ProFLEX heavy-duty with Bluetooth.

See 4 Bluetooth Heated Insoles With App

You’ve got the two insoles, got the battery charger with the two batteries in it, charging cord, part that plugs into the wall, the instructions, one disclaimer telling you that these work different than chemical heaters that you’re used to, a customer service card and then a bag to throw everything together when you’re done using them. Really nice that they actually provide a bag. You slip these in there, throw the charger in with it, you’re all set to go.

The insoles themselves are pretty straightforward. They are soft, there’s a little bit of a tab in the back so when it’s down in your boot you can pull it out.

Flip it over, there is a little bit of a line, you can trim it to a certain point to fit your boots a little bit better. If you look really close there’s a number that identifies each one of your insoles. You’re going to want to write that down and remember. That helps you when it comes time to sync with your Bluetooth.

Let’s look at the charger. Battery goes in either side. Micro USB plugs in the charger and USB plugs in the part so you can plug it into the wall. Otherwise if you want to put it in your car, possibly a computer, since it’s USB, you can do it that way.

Now let’s talk about the batteries. When you pull them out of the charger, it has to be slid out. If you pull it up all the way out you could crack off a little red piece and that’s what charges it up. So make sure you’re sliding in and out and that goes with the insoles as well.

When you’re powered up, what you’re going to see is it’s going to blink red and green for 10 to 15 seconds and that’s just letting you know you have power to the insole now.

The battery itself is really soft so you’re not really going to feel it too much when you’re walking around. As far as sizing goes, you can flip it over, you can find it at the bottom on the heel. The sizing actually is pretty decent. If they’re a little bit too big, you can flip them over and you can trim it. It gives you the line. You don’t want to go past that line because that must be where some of the coils and stuff are in there and you don’t want to damage those but you can trim them a little bit to fit your shoe or your boot or whatever you put them in.

Here is a sizing chart:


Let me show you how to get that free app as well as how to use the thing.

Go to the app store, search ThermaCELL. The product app comes up. Download that. Once that’s done, you’re going to see it on your desktop. Go to settings, Bluetooth. The two numbers that are on the top are the ones that correspond with the numbers that are inside the battery compartment on the insoles. It shows that they’re not connected. Do not connect them now. The app will actually connect them. Go to the app and then you can register.

You are going to add nearby products. You’ll get the opportunity to name yours. Hit add now. When you first set up your device, it’s going to ask you for a four-digit code to unlock the heated device. Put the number in, hit submit. It will show that your insoles are inactive. Click on the name you gave and now it takes you to the main screen that you’re going to use.

What is showing on the left and the right is how much battery is left in the left insole and in the right insole. You can switch it to low, medium or high. The other thing that’s kind of cool is you can link them. If you don’t link them, you control them independently. If you link them, they’re both on the same temperature setting.

Now if you back out of this app, it’ll stay running in the background. Just because you back out of the app doesn’t mean they’re going to shut off. They do stay on in the background.

thermacell foot warmers

Moving on to some testing. The first thing we’re going to look at is these lithium ion batteries. The claim is that they charge in less than two hours and you’re supposed to be able to charge them as many as 500 times.

When you put the batteries in the charger, you’re going to see orange lights come on. That means the battery is not fully charged. Each battery has a separate light. For this test I completely drained both batteries before putting them in. After one hour and 51 minutes the first battery became completely charged. Three minutes later, at one hour and 54 minutes, the second battery became completely charged. Both green lights came on in less than two hours. So I guess that checked out okay.

These batteries are supposed to last eight and a half hours on low heat when the insoles are powered up. We’re going to test that out. The battery is completely charged. I turn the left insole on low and the right insole on high. Put together a time-lapse hour-by-hour until the batteries were completely dead.

For this test the insoles were not in a boot, they were sitting out in a pretty ideal condition, about 67 degrees. The battery on low made it seven and a half hours with temperatures ranging from eighty to ninety nine degrees. Seven and a half is just shy of the eight and a half hour battery life as advertised.

The battery on high only made it four and a half hours with temperatures ranging from 105 to 113 degrees Fahrenheit. If you’re wondering how those temperatures compared to the advertised temperatures, on low setting the insoles are supposed to reach a hundred degrees and I saw temps up to 99 degrees which is right on. As far as the high setting, temps are supposed to reach 115 degrees. I measured temperatures as high as 113 degrees which is also pretty close.

The next thing that I wanted to do was a temperature test looking at the hot and cold spots on these insoles using the infrared surface to monitor and since a lot of you guys are familiar with chemical hand warmers, I’m going to throw one of those into the mix as well.

After 20 minutes the chemical heater was only in the 90s, even though the max advertised temperature for this particular product was 156 degrees. I know from experience that these things will get way hotter but 20 minutes obviously was enough to crank it up. On the flip side, the insole did reach max temperature in only 20 minutes.

The hottest part of the insole was just past the ball of your foot up by the toes, right in the middle. Temperatures during this test reached 112 degrees Fahrenheit. The rest of the insole didn’t really heat up much at all, especially around the heel, by the battery, it stayed about room temperature.

This test showed me two things. The first thing is that the insoles warm up closer to the toes where people’s feet typically get colder. The second is that even though I know these chemical heaters get way hotter than these insoles do, it seems that the insoles get to a maximum temperature a lot faster.

Now I want to talk about real-world field testing that I did with these products.

The first time that I used them, a huge snowstorm came ripping through, followed by temperatures that were well below zero degrees outside and I knew I had to get in a tree stand for some late season bow hunting. I had a long walk to my stand so I figured these heated insoles, perfect. Light boots, light socks, I can walk to my stand no problem, not lugging big boots with me and I’ll flip them on when I get to the stand.

I should have done a better job of reading the directions and trying to figure these things out first because it was a disaster. Within an hour my feet were absolutely freezing to the point where I was on the border, probably, unsafe. Got out of my stand, head back to the cabin. So the first outing with these things, not so good. But before returning them or even throwing them in the garbage, I decided to actually open up the instructions, read it, go online, see what some other people had to say about it and try to figure these things out a little bit more.

Two problems here. The first one was uninsulated boots. I thought I could just get to my stand, flip my phone on, these things would heat up and I’d be fine. Not the case. You got to have some kind of insulated boot to keep the heat in and that was definitely my bad.

But the second thing was, I really ran out of room and it was a tight fit. I took the original insoles out of my boots, put the ThermoCELL insoles in and when I put my boots on there wasn’t really much room for air to circulate around my foot or anything like that. So it was a pretty snug fit. You need to have a little bit of extra air around your foot so that air can warm up and warm your foot up.

The light sock was actually okay. I just needed to have a little bit more air, a little bit more space around my foot to heat up, to keep my foot comfortable and then again have an insulated boot to not let the heat out.

So strike one but that was my fault.

So after doing my due diligence and trying to figure out actually how these things worked, I use them for a second time.

Besides late-season bow hunting, you can always count on cold weather in another place and that’s a playoff game at Lambeau Field. Kick-off temperatures were about 10 degrees and I spent four hours tailgating as well as three and a half hours in the game, so I was outside for probably seven to eight hours. This time around I put the insoles in a little colder weather boot, 1,200 grams thininsulate and for whatever reason, my later season boots were a little bit bigger, one size bigger, so I had plenty of space and air around my sock and around my foot.

I will tell you that over the course of that game, I’m standing on cold concrete the whole game, I did not have any issues whatsoever with my feet getting cold. So I had these things on medium all day with no issues whatsoever.

The interesting thing about it is with chemical heaters you can feel how hot they’re actually getting, too hot where if they’re on your skin they may even burn you. You don’t even realize that these are on but if you start thinking about it then you’re like my feet aren’t cold they’re just comfortable. So the best way to describe it is just kind of a warm glow.

So the Packer game was a way bigger success than my late season bow hunting outing. I had the right pair of boots on, the right pair of socks on, the right amount of space are on my foot to let that air circulate and my feet weren’t cold whatsoever.

So that’s it for the field tests.

We can move on to pros and cons.

See Remote Control Heated Insoles by ThermaCELL.


1. It comes with a bag. Might not seem like a big deal but I’ve got so much hunting stuff that at least I can put all this stuff in one bag and not lose a bunch of cords or get it messed up with all my other junk.

2. I found the app to be user-friendly. Not only to download and figure out how to use but also to use in the field. Just make sure you guys keep your cell phones charged up.

3. The battery’s comfortable. This is one thing that I thought I was going to have a big problem with, especially at the football game standing seven to eight hours. I mean your heel is right on top of that battery but it’s padded enough that you don’t even know you have it in there.

4. The batteries charged up quick, less than two hours. The great thing about that is, morning hunts, you come in for launch or you go back to your truck or whatever, two hours you get them both charged back up, put them back in your boots and you can go for an evening sit.

5. I’m going to list the battery life as a pro even though it didn’t make it to the 8 and a half hours as advertised. Seven and a half hours is a pretty good run. If you’re going to hunt all day and you don’t have an opportunity to go back to the cabin, the house, your truck to charge these batteries up, you can buy a second pair, get them charged up that will take you through the rest of your hunting day.

6. They actually work. Provided you do everything right, you don’t make a bonehead mistake like I did while I was bow hunting, but they do keep your feet warm.

7. They don’t get so hot that your feet get sweaty and/or you have to worry about chemical burns if they’re right against your skin.


The only drawback that I found with this product is really just having the appropriate size of boots. So like I talked about my early season boots, they fit really well, I wanted to fit as close to a running shoe as I can. If I got to walk long distances, I got to climb trees, I don’t want to have a lot of extra space and be lugging these big boots around.

But in that situation you have no room. These insoles are a little bit bigger than the original insoles of your boots so you don’t have the space to have the appropriate amount of air circulating around your foot to keep your foot warm. When I made the switch to the bigger boots, luckily I had boots that were big enough and allowed for a little bit more air circulation around my foot, that these things work really well.

So I guess my advice to you would be either take your boot to the store, put the insole in and make sure you have enough room for your foot to breathe or at a minimum if you’re getting these things shipped to you, at least try them on before you go out in the field to make sure that it’s going to warm up the way it’s supposed to. All in all as long as you guys don’t do what I did, I think it would be fine.

Now we’re going to move on to cost and where to get it. At the time of making this review, I found these heated insoles here for right around $200. Click here to see what the current price is.

One more thing before I end this review. Limitations. These insoles are supposed to be water-resistant and I decided not to test that. I buy my boots to be water resistant so if I got water coming in my boots I got bigger problems than my insoles becoming wet.

thermacell proflex rechargeable heated insoles

See best rechargeable heated insoles review and read about remote control heated insoles.

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