The heatwave is approaching, and with it, temperatures above 30 degrees. In France, this kind of weather makes the body sweat – it’s even worse in India, Japan or Singapore for example, where extreme temperatures are accompanied by humidity levels often above 80%.

Sony’s start-up incubator and crowdfunding platform, First Flight therefore invented Reon Pocket, a portable mini air conditioner for the moment only available in Japan and sold for a little over 120 euros.

The device is controlled via a bluetooth application and requires a special t-shirt, which has a pocket in the hollow of the shoulder blades.

According to Sony, it can cool the body temperature up to 13 ° C for two to three hours – the life of its battery. An assertion that The Verge wanted to test, and the results of which turned out to be more or less convincing. The Reon Pocket looks very comfortable; lightweight and placed in a well-fitting pocket, it is barely noticeable and felt.

On the other hand, its cooling capacities are mainly localized on the contact zone between the device and the body. Once you move away from it, the device loses a lot in efficiency, an impression that Sony’s explanatory photos confirm.

Tricking the brain with the Peltier effect

Whether in cooling or heating mode, the Reon Pocket is based on the Peltier effect, a thermoelectric physical reaction which designates the displacement of heat which takes place in the presence of an electric current. The object does not really change the temperature of the body – which is essential, the proper functioning of the latter relying on a well-functioning thermostat system.

The idea is rather to trick the brain into believing that its temperature is colder or warmer by a few degrees. A system that is already inspired by other products such as the Embr Wave, a connected bracelet that can reach the temperature of an ice cube or a hot drink depending on the settings.

These inventions still fall far short of the ideal of the lightweight, air-conditioned polyester underwear, closed around the neck, wrists and ankles (and powered by batteries) that Lee Kuan Yew, the very Prime Minister of Singapore, dreamed of at the end of the last century.

“Historically, advanced civilizations thrived in cooler climates, he explained. Everyone could then work at their optimum temperature and civilization could extend to all climates. ” Words that resonate even louder as the planet is expected to warm by 6.5 to 7 ° C in 2100, according to the worst-case scenario, and that the climate of New York City is now considered subtropical.