The article reviews a wearable cooling device known as a fan jacket, inspired by Japanese designs originally developed in the early 2000s by a former Sony engineer to help outdoor workers cope with extreme heat.

The reviewer tests a replica model, the Fernida fan jacket, purchased via Amazon during a UK heatwave, aiming to assess whether it can provide effective relief from high temperatures.The jacket functions by using four small battery-powered fans embedded in the garment, circulating air throughout the inside of the clothing.This airflow is trapped by the nylon material, which helps retain and direct cool air upwards through the collar and sleeves.

The device is powered by a 10,000mAh rechargeable power bank included with the jacket, which also serves as a charging source for other devices such as a smartphone.Users can switch between four fan speed settings via the power unit.

In practical testing during temperatures of around 28–30°C, the jacket is reported to deliver strong and noticeable cooling, effectively reducing body heat and making both indoor and outdoor activity more comfortable.However, the experience comes with drawbacks.

The jacket inflates slightly when in use, creating a bulky appearance, and the fans are audible, though not excessively loud compared with handheld alternatives.The main limitation is battery life.On the highest setting, the jacket lasts around one hour, while lower settings extend use to approximately three hours.The battery cannot be recharged while the fans are running, and recharging the power bank itself takes around two hours.

At a price of roughly £72, the jacket is considered highly effective in terms of cooling performance but significantly constrained by its limited runtime.

Overall, the product is described as one of the most effective portable cooling solutions tested, particularly suited to outdoor work or short-term use during extreme heat, but held back by poor battery endurance.