When you're out on a cold day, it's often your fingers that feel it most. That's no accident: when the temperature drops, our bodies switch to survival mode and prioritise sending blood and warmth to our essential organs.
But when you're off on a long walk or working outside for hours on end, this can become pretty unpleasant. Which is where the best hand warmers (opens in new tab) come in, helping to get life back in your frozen fingers at the touch of the button.
The Lifesystems rechargeable hand warmer (opens in new tab), which we reviewed in 2021, was previously top of our list of best buys. But the company has now brought out this new version, upgraded with a new 10,000Mah battery: double that of its predecessor. That means it offers up to 14 hours of warmth rather than six, and it only costs a little more. So is it worth investing in? We put one to the test to find out.
Note: this product is also called the Lifesystems Rechargeable Handwarmer 10,000 in different territories.
Lifesystems Hand Warmer XT review: Features & Usability
The Lifesystems Rechargeable Hand Warmer XT comes in a box with a small cable that connects it to USB-A. That means you can charge it from the USB-A port on your computer, or a wall plug with a USB-A input. At the connector end of the device, there are four orange lights. Once all four are lit up, your device is charged.
To activate the heat, you simply press the 'on' button on the side, and the device will warm up very quickly. This happens in a few seconds, although I found that to really feel the benefit in my hand took a few minutes.
There are four heat settings, which you can scroll through by pressing the 'on' button. I found that the lowest setting did have a noticeable effect when I was indoors at room temperature, but when I was out in the cold (around 5 degrees Celsius), I needed levels three or four to make the difference.
One niggle is that it took me quite a while to charge to full: about two and a half hours plugged into the wall. Also, when I didn't use it for a couple of weeks, it then lost the charge it had, so I had to charge it up again. (To be fair, Lifesystems do say in the small print: "Charge the hand warmer periodically to maintain optimum battery condition").
Lifesystems Hand Warmer XT review: Performance
The Lifesystems Hand Warmer XT offers between 6 and 14 hours of heat, which sounds impressive. But as you'd expect, the higher the setting, the less time you'll get. Also, in the small print, you'll find these qualifications: "All specifications based on 20 degrees C ambient temperature. Exposure to extreme low temperatures may affect efficiency. For best results, keep inside a pocket or glove."
Maybe people from warmer countries than my own (the UK) would feel differently, but personally I'm unlikely to use any hand warmer unless the ambient temperature is below 20C. That said, when I took the hand warmer on walks of two hours plus, in temperatures between 3C and 8C, it still worked fine and had battery left at the end of it.
The good thing about the Hand Warmer XT specifically is that it has dual heat plates, which means that the warmth radiates evenly across the whole surface, rather than being concentrated in one place. As the small print suggested, I found that using it in my pockets worked best, creating a rosy aura of warmth around my pinkies. Just holding it in the frigid air, however, was less satisfying. It does get pretty hot, though, with a max temperature of 53C, so you can't really complain about lack of heat.
An added benefit of the XT is that you can also use it as a power bank, via its USB-A port. This worked well in practice: it's not the fastest charger I've ever used, but if your phone is dying on a long walk, it's a nice backup to have. Note, though, that you can't warm your hands and charge your phone at the same time.
Lifesystems Hand Warmer XT review: Verdict
The Lifesystems Hand Warmer XT is a well designed device that's easy to set up and charge. It's fits comfortably in the hand, and isn't too heavy at 198g. Overall, it does the job it's designed for very well. Do note, though, that the hand warmer is water-resistant, so it can be used in the rain, but not waterproof, so you shouldn't take it cave diving or anything like that.
Also, be aware that to fit in the bigger battery, it doesn't have a handle like its lower-powered cousin, Lifesystems Rechargeable Hand Warmer (opens in new tab). So, if storage trumps battery in your eyes, you may prefer its predecessor. The Lifesystems Hand Warmer XT also costs a little more than the Lifesystems Rechargeable Hand Warmer, and while the bump in price isn't much, it's worth considering whether you need that extra battery.
How often are you likely to want to warm your hands for several hours at a time? If 'rarely' or 'never' is your answer, you may just want to save your pennies and go for the XT's cheaper cousin. If it's 'often', though, then this powerful, long-lasting hand warmer has a lot to recommend it.
