While there are tonnes of brands selling fan jackets in Japan – from Kuchofuku, Makita and BurTle – none of them have yet made it to UK shores. Rather than spending hundreds of pounds importing one across the world, I spotted a replica fan jacket on Amazon and snapped it up. It might be the best decision I’ve ever made.Made from nylon, Fernida’s fan jacket is a bit like wearing a zip-up windbreaker. There are even two pockets on the side. Nylon’s a great material for a fan jacket because it’s better at trapping the airflow inside your clothing before escaping through the collar and cuffs. It’s also super lightweight to wear (very important given you’ve got four fans stitched into the inside weighing you down).Two fans sit on either side of your back – one pair of fans at the bottom and one closer to the top. It actually looks pretty cyberpunk from the rear and you can actually see the four fans spinning. But how does it work?Fernida’s fan jacket comes with a 10,000mAh power bank in the box, which doubles up as the power unit. There’s a cord on the left side that connects the four fans together. Plug that cord into the power bank, turn on the power bank by holding down the power button and watch as the fans kick into gear. There are four fan speeds that can be cycled through using the power button. Once you’re happy, you can just pop the power bank into the little internal pocket and off you go gallivanting in the sun. You can even ue the power bank to charge your phone or other devices. It does inflate a little, making you look like Michelin Man (Alex Lee/The Independent )But was it worth the purchase? I’m pleased to say that Fernida’s fan jacket is everything I’ve ever wanted. The fans are extremely powerful, blowing around and up your entire body. Because the fans get trapped inside your jacket, it almost creates a funnelling effect. The air escapes through your collar, so it even lifts air upwards, cooling your neck and your face from below.I’ve been wearing it in 28C weather, and it has been absolutely glorious – both indoors and out. I’d liken the cooling effect to having fans directed at you from all directions. It’s fantastic, and reduces my body temperature by several degrees. I honestly don’t want to take it off.I’d recommend wearing a sweat-wicking T-shirt or a vest underneath – aka something loose so the airflow can better circulate. The air gets stuck in the jacket that makes it inflate a little bit like a balloon, so you do kind of look like a bulbous Michelin Man. But when it’s this hot outside, who cares?You can definitely hear the fans running, but surprisingly, it’s not as loud as putting a handheld fan to your face. I’ve got a high tolerance for noisy things though, so your mileage may vary with regards to volume. The fans plug into a power bank, that can be tucked into a little pocket (Alex Lee/The Independent )It comes in sizes S-XXL, and while you can wash the jacket in the washing machine by taking out the fans, I’d recommend hand-washing it – it’s very fiddly to put it all back in. There is one major downside to the jacket, and that’s battery life. On the highest setting, the fans only ran for about an hour before running out of battery. On the second fan setting, I was able to eke out roughly 3 hours before it died. That’s pretty useless. And annoyingly, you can’t charge the power bank while plugged into the fans – so you can’t extend the battery life by plugging the power bank into another portable charger. The power bank itself takes about 2 hours to charge back up. If you’re working outdoors or at a festival, you’re probably going to want it to last a little longer than three hours on a single charge. Key specifications:Fan speed settings: 4Battery life: One hour (on the highest setting)Sizes: S-XXL