An earbud-type wearable (A hearable) with vital parameter sensors for early detection and prevention of heat-stroke.

Heat-stroke has become a serious problem in Japan, especially for elderly citizens. For the early detection and prevention of heat-stroke, a wearable health monitor for in-ear use is developed which is subsequently called "Hearable". It aims to measure three vital parameters: Core body temperature, sweat rate and sweat or interstitial sodium ion (Na) concentration.