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Sony Reon Pocket 5 hands-on preview: A personal heating and cooling device in wearable form

Image of the Sony Reon Pocket 5 on a table with the long vent attached

Sony’s Reon Pocket 5 wearable has been given a mid-May release date in the UK following the success of its predecessors in Asia

The Sony Reon Pocket 5 – a wearable device designed to adaptively warm you up or cool you down – is coming to the UK next month.

Launched as a crowdfunded proof of concept in 2019, the first two iterations of the Reon Pocket proved a hit in Japan. This led Sony to start selling the third-generation model in Hong Kong in 2022 and strong sales saw a fourth model released in those markets last year.

Sony believes the time is right to bring the product to the West and the new Reon Pocket 5 can be preordered now for £139, with units shipping from 15 May.

I spent some hands-on time with the Sony Reon Pocket 5 and you can read my initial impressions below. But before I jump into those, let’s find out a bit more about what it is, how it works and some of Reon Pocket 5’s potential use cases.

Sony Reon Pocket 5: What is it?

The Reon Pocket 5 is a “wearable thermo device” that uses a Peltier element powered by an internal battery to help regulate your body temperature. It is not a medical-grade device, however; this is a lifestyle wearable that will simply provide a bit of warmth or cooling when required. 

It comprises three separate components: the main unit housing a thermal module, an adjustable neckband that this unit slots into, and the Reon Pocket Tag, which has built-in sensors to measure the temperature and humidity in your environment. There are five sensors in total: three that record temperature, one that measures both temperature and humidity and one that measures motion.

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Sony Reon Pocket 5: Who is it for and where can it be used?

The Reon Pocket 5 has proved particularly popular with commuters in Asia according to Sony but can be used in a wide range of circumstances.

Its warming capabilities should be welcome on a chilly morning walk or at home when you don’t want to put the central heating on. On the flip side, I envisage its cooling will come in handy at outdoor events on hot days or as a backup if your portable air conditioner goes kaput and you don’t have access to a fan.

Sony Reon Pocket 5: How does it work?

The neckband holds the main unit against your back just below your neck and when one of the four warming levels is engaged, the side of the Peltier element touching your skin warms up. Because the device is worn under an item of clothing, the heat generated is retained and gradually spreads down your back and arms, resulting in a rise in your body temperature.

Conversely, when one of the five available cooling levels is active, the stainless steel section against your back becomes cool to the touch to help lower your body temperature. The cooling effect is sustained by a fan that draws hot air away from your body and pushes it out of a small plastic vent attached to the unit which protrudes from the top of your shirt.

Image of the Sony Reon Pocket Tag clipped to the pocket of a shirt

Control of the device is managed in the Reon Pocket companion app, which is available on both iOS and Android. You can adjust the level of cooling or warming manually or have the device do so automatically using its Smart Cool ⇔ Warm mode.

This takes the measurements captured by the Reon Pocket Tag and engages an appropriate level of warming or cooling based on your movement and environmental conditions. It’s customisable too, with options to set the parameters within which the various warming or cooling levels kick in.

When taken off, the Reon Pocket 5 will automatically deactivate the Peltier element, reactivating it as soon as it’s back in position against your skin. This helps conserve the device’s battery life, which is highly dependent on which of the Warm or Cool levels is in use.

With the lowest level of cooling (Level 1), battery life is approximated at 17hrs. That figure falls to 12hrs at Level 2, 10hrs at Level 3, 7.5hrs at Level 4 and just 4hrs at the coolest Level 5 setting. The warming functionality is more battery-intensive, with the Reon Pocket 5 able to last around 8hrs at Level 1, 6hrs at Level 2, 5hrs at Level 3 and 4hrs at Level 4.

Sony Reon Pocket 5: Initial impressions

I didn’t have a huge amount of time to put the Reon Pocket 5 through its paces, nor was I exposed to the kind of conditions it’s going to be most useful in. As such, I came away with more questions than answers about the device’s performance.

Its most powerful Warm setting is certainly capable of generating a decent amount of localised heat, however, and I enjoyed the sensation of it doing so across my back. I’d compare the feeling to that of wearing a Deep Heat patch. I gradually became more aware of the heat emanating from the device as it warmed up but didn’t have enough time to see how effectively the heat spread or what impact it had on my overall temperature.

It was a similar story with the Cool settings. Being indoors on a relatively nippy spring day meant I wasn’t crying out for being any colder, but I could pick up on a noticeable difference between the highest and lowest cooling levels. The highest level certainly seemed cool enough to have the desired effect but only extensive testing will tell whether it will be sufficient to assuage the horrors of a rush hour Tube on a sweltering summer’s day.

I was impressed by how comfortable it is to wear, however. With dimensions of roughly 55 x 23 x 117mm (WDH), I feared it might feel like a millstone around my neck but it’s lightweight enough to forget about once it’s in position. It doesn’t require any adjustment either. Once in place, it will stay there until you decide to remove it.

Image of the Sony Reon Pocket 5's fan vents

The app seemed reasonably intuitive to navigate and provides a decent amount of scope where personalisation is concerned, too. Given the personal nature of what the Reon Pocket 5 is trying to achieve, having the ability to make granular adjustments is extremely important and those options look to have been implemented well here.

That said, I’m a little concerned about battery life. I imagine people will gravitate towards the top heating and cooling settings for greater impact and four hours of use in these will mean the Reon Pocket 5 requires topping up regularly. A full charge will take approximately 170 minutes but you should be able to get around 90% charge in 100 minutes, which isn’t too shabby.

Ultimately the Reon Pocket 5 will live or die on the extent to which its heating and cooling effects spread from their source and how effectively it adapts to changes in environmental conditions.

Preorder now from Sony

We’ll be testing those things thoroughly when we get our hands on a review sample of the Sony Reon Pocket 5 but if you can’t wait until then, it’s available to purchase now for £139.

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