The device includes a housing, a flash lamp arranged inside the housing, the housing having an opening through which electromagnetic energy originating from the flash lamp can be transmitted towards a skin surface. The housing includes a cavity adjacent to the flash lamp; at least one aeration orifice; and at least one mobile component in the housing, which can be displaced between a first so-called aeration position, in which the cavity communicates with the aeration orifice and a second so-called closed position, for which the cavity is closed in order to limit the light escaping from the opening. The mobile component can be formed by a housing portion that can close the cavity except for the opening, by moving towards a complementary housing portion