I used L'Oréal's tiny wearable to keep me safe in a heatwave

It's hot. Like, real hot. For those reading this who aren't in the UK, we're currently experiencing a massive heatwave. Temperatures have already hit 33 degrees centigrade (91 degrees Fahrenheit) – which is significant, for us.

It's been prime shorts and shades weather for a few weeks now, so I took it as the perfect opportunity to test out a wearable that's all about keeping you safe in the sun. Specifically, your exposure to dangerous levels of UVA radiation.

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L’Oréal's MySkin Track UV wearable sensor launched in the US late last year, but is now on sale from the Apple Store and other select retailers. I've been wearing the MySkin Track UV the past month to find out how it goes about protecting you from those harmful rays, and to see if it's any good. Here's what happened.

How it works

Before I get into my experiences of wearing the the sensor, I'll explain how it works. What you have here is a very small wearable (we've shown the scale in the image above) that sits inside a clip. When I showed it to one person, they said it looked a bit like a hair pin, which is fairly accurate.

Inside that hair-clip-looking device is an LED that is used as a detector to capture UV light. The data is transferred from the sensor to your phone via NFC (Near Field Communication), coming in to the companion smartphone app. You'll need to tap the sensor against the NFC-friendly part of your phone to sync the data and it'll then display your current level of exposure to dangerous levels of UVA radiation. It can also calculate UVB exposure and is apparently able to store three months' worth of data.

There's no battery here, so you don't ever need to charge it, and the nature of the design means you can wear it in multiple places, which I'll get into next.

Getting set up

The first thing you'll need to do is download the My Skin Track UV smartphone app, which is available for Android and iOS devices. Our experiences were based on using the Android version on a Google Pixel 2 XL. Once you've downloaded the app and named your Skin Track sensor, you'll be reminded that all the data is stored locally and not shared elsewhere – which is good to know.

Next, you'll need to input your skin tone from a colour scale. This is important because different skin tones can impact on the the effect of UV exposure, so the sensor's readings are adjusted on that basis. You'll then have to choose your 'main skin concern'. I put down oily skin, though I can't say it's something that particularly concerns me day-to-day.

You'll need to grant the app access to location data to provide the additional data insights that you don't get from the sensor, but you do get in the app. So things like weather conditions, air quality level and pollen index information.

Then it's time to decide where you are going to wear the My Skin Track UV. The options suggested are hat, sunglasses, t-shirt collar/neck area, short sleeves, long sleeves, wrist area and shoes. By entering this information, the app can then offer the most accurate readings.

My initial decision was to wear it around the t-shirt collar/neck area. But I quickly discovered this was a problem because I don't wear the same t-shirt every day. The chances of me forgetting it on a shirt I'd worn the day before were high. So I had to pick somewhere that made more sense.

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After trying it on clothes, I decided to wear it on my watch strap, which was one of the suggested areas and I was told would be good fit. My watch (or whatever watch I'm testing) stays on my wrist pretty much all the time and it felt like an unobtrusive place to wear it. I had it clipped onto the Garmin Marq Athlete, the Forerunner 945 and the Polar Ignite over the course of testing.

On the Athlete, the sensor did not budge from its position and I was pleasantly surprised at its ability to stay put. I even wore it swimming and it remained in place. When I moved to wearing the 945 though, things changed. While the wearable didn't budge, it did start to slip out of position and look increasingly likely it was going to fall off.

Then it did fall off. Twice.

The first time I was fortunate that it fell below me while I was in the pub and I was able to retrieve it. The second time I thought I had lost it for good. Fortunately, having spent the day lamenting the loss of the £60 wearable, I was amazed to find it was in my bed and had clearly fallen off my watch when I was asleep. Not great.

Time to (safely) soak up those rays

Using the My Skin Track UV is as simple as wearing it and, when prompted by a notification on your phone, scanning it. That scanning process will differ depending on what phone you have and where the designated NFC area on your phone lies. In my case, that was on the back of a Pixel 2 XL near the rear-facing camera.

Scanning requires pressing the front of the sensor with just enough pressure to be recognised by the app. The scanning takes a few seconds and then is added to the 'Your UV Exposure' gauge, giving you a percentage of your day's exposure.

That scanning process can be a touch on the fiddly side though. It usually didn't scan on the first attempt, requiring you to move it around the back of the phone to find that sweet spot. When the data is scanned and synced you'll usually see a notification about the UV index for the day. It'll offer pretty generic messages to use sunscreen with high UVA and UVB protection and to apply frequently. When your skin has been exposed to 100% of your maximum sunstock you'll see a similar message.

You can see exposure trends over days, weeks, monthly and yearly inside the app, but the onus is to frequently scan when prompted to, which can feel quite nagging at times. While the sensor is supposedly capable of storing months of data, I noticed gaping holes appearing in graphs unless I synced frequently.

The rest of the dashboard inside the companion app is made up of insights into other environmental factors that can be detrimental to your skin and your health. So there's an Air Quality level meter and a pollen index, which was useful for a hayfever suffer like myself, though that information can also be found in other places like the Apple Watch, which pulls the data through from a weather app.

Also in the app is a Skin Advice tab, which is a bit like a La Roche-Posay store front, recommending products that are good for your skin problem and offering tips to take better care of your skin.

Then there's Activities, which is an interesting idea where you track an activity like running or cycling using your phone's GPS. You'll be prompted to scan the sensor at the beginning of the activity and then at the end to offer UV, pollen and air quality data. I purposely took it out on a pretty hot day (screenshot above) and it collated my data in a really clean and appealing way. It made me think how good it would be to actually have this capability inside a smartwatch or a sports watch though.

Here comes the break…

On the whole I quite liked the idea of having a wearable that was doing something a bit different and it did have me thinking more about UV exposure. The app is nicely designed, the device was comfortable and easy to wear on the whole – until it started to fall off, which is clearly a problem with this device. The notifications and responses to my data could certainly have done with being a bit more varied and less generic. I'd like to think most people know that they should be frequently reapplying sunblock when out in the sun. At the very least it was getting me to be more aware of sun exposure, especially when out running.

But then an even bigger problem arose. On the day I started to write about my experiences, the sensor just broke. I went to scan it as usual and the casing protecting the sensor just fell apart. The casing had cracked, leaving the tech inside exposed and my £60 UV-detecting wearable no longer wearable. It can still scan, but it can no longer be worn. I can't really explain why or how this happened, but that casing clearly doesn't seem fit for purpose.

So while the MySkin Track UV was able to make me think more about UV exposure, it also got me thinking how this expensive wearable clearly needs to be built better. If L’Oréal can fix these problems, I'd consider wearing it again. As for the heatwave, it's not yet relenting, but I'm at least a little wiser on the effects it's having on my body.