The present disclosure relates to the fields of medical technology as well as fitness and activity trackers. To provide improved wearing comfort, in particular by reducing skin irritation, a wearable device (10) adapted to be worn by a user (100) is presented. The wearable device comprises a fixation element (12) for fixing the wearable device to the user; a lower side (15) for contacting a skin (101) of the user when worn; and a processing unit (20) adapted to determine a sweat level measure (32) indicative of an amount of sweat accumulated between the lower side (15) of the wearable device and the skin (101) of the user and indicative of an exposure to sweat over time; and to determine a moment in time for ventilating said lower side of the wearable device based on a said sweat level measure (32). The present disclosure further relates to a corresponding system and method.