A device intended to reduce the risks of overexposure to harmful solar radiation. The device includes a detection arrangement, including at least one sensor sensitive to solar radiation, in particular UV. In addition, an arrangement is linked to the detection arrangement to generate a signal representing the quantity of radiation received by the detection means. An attachment arrangement is provided to attach the device to the head of a subject, such that the sensor(s) is (are) oriented in a substantially perpendicular manner to the vertical plane of the subject when the latter is active in the sun. The device is preferably configured in the form of a cap, with the detection arrangement arranged on a first visor intended to be positioned over the back of the individual's neck. The cap also preferably includes a second visor located opposite the first.