Device for measuring a plurality of temperatures with the aim of determining a core internal temperature of a human being wearing said measurement device, the measurement device having a first face and a second face opposite the first face and being configured to be able to be in a worn configuration in which the measurement device is at least partially wound over itself and forms at least one cylindrical portion having an axis, the first face being turned towards the axis, the measurement device, in its worn configuration, being intended to at least partially encircle an arm of the wearer, in the vicinity of a corresponding armpit of the body of the wearer, so that the axis of the measurement device is substantially merged with the axis of said arm, the first face of the measurement device then being in contact with the skin of the arm of the wearer, characterized in that the measurement device comprises: - at least three skin temperature sensors configured to measure a skin temperature of the wearer, the skin temperature sensors being positioned on the first face of the measurement device, in a first zone of the measurement device, and extending substantially over at least part of a peripheral line of the measurement device in the worn configuration; - at least one cavity temperature sensor configured to measure a temperature in said armpit of the wearer, the cavity temperature sensor being arranged on the second face of the measurement device, in a second zone of the measurement device; said first zone of the skin temperature sensors and said second zone of the cavity temperature sensor or sensors being arranged at least partly facing each other or being substantially adjacent, projecting in a plane orthogonal to said first and second faces (31, 32) the device being configured to be able to be in an unworn configuration in which it is substantially flat the device also comprising at least one proximal temperature sensor configured to measure a surrounding temperature in the immediate vicinity of the arm of the wearer, the proximal temperature sensor being arranged on or near the second face of the device, the device also being characterized in that, in the unworn configuration, the distance between a skin temperature sensor and the at least one proximal temperature sensor is greater than 10 cm. - at least three skin temperature sensors configured to measure a skin temperature of the wearer, the skin temperature sensors being positioned on the first face of the measurement device, in a first zone of the measurement device, and extending substantially over at least part of a peripheral line of the measurement device in the worn configuration; - at least one cavity temperature sensor configured to measure a temperature in said armpit of the wearer, the cavity temperature sensor being arranged on the second face of the measurement device, in a second zone of the measurement device; the device being configured to be able to be in an unworn configuration in which it is substantially flat the device also comprising at least one proximal temperature sensor configured to measure a surrounding temperature in the immediate vicinity of the arm of the wearer, the proximal temperature sensor being arranged on or near the second face of the device, the device also being characterized in that, in the unworn configuration, the distance between a skin temperature sensor and the at least one proximal temperature sensor is greater than 10 cm.