Wearable fans, neck rings and cooling towels

The body sheds heat through the skin, and it does so far better where blood runs close to the surface: the neck, the wrists, the temples. That is the physiological reason a fifteen-euro neck ring changes how you feel more than a fan two metres away.

Three families sit here, and they do not serve the same moment. Wearable fans — neck, waist, clip — move air continuously as long as the battery holds. Gel rings and caps take heat by contact for one to two hours, then recharge. Dense-weave towels hold cold by evaporation and restart with a snap.