A safety helmet (10, 20, 30, 40, 50, 60) including a rigid outer shell (11, 21, 31, 41, 51, 61) possibly provided with at least one external air intake opening (12.1, 12.4, 32.1, 42, 48.3, 54.1, 62), and at least one external air extraction opening (13.1, 23.2, 23.3, 33.2, 49, 49.1, 54.2, 63) provided on the external shell for introducing and extracting air, respectively, into and from said helmet, said helmet including an inner part (11.1, 21.1, 31.1, 41.1, 51.1, 61.1) made to absorb and deaden any impact endured by said helmet and having possible transverse and/or longitudinal grooves obtained in at least one portion of said inner part, possibly extending from the front zone to the rear zone of said inner part and passed through by the air introduced through at least said external air intake opening (22.4, 54.1) and at least said external air extraction opening (23.3, 54.2), at least one of said longitudinal grooves (21.2, 21.3, 47.3, 47.5, 51.2, 51.3) forming a respective and possible frontal air intake opening (22.1, 52) and a respective and possible back air extraction opening (23.1, 53), and comprising an inner padding (14c, 24c, 34c, 44c, 54c, 64c) which provides by means of a plurality of canalizations a canalization structure (16, 26, 36, 46, 50.1, 66) for conducting air: - between said at least one frontal air intake opening (22.1, 52) and/or at least one external air intake opening (12.1, 22.4, 32.1, 42, 48.3, 54.1, 62) and said at least one back air extraction opening (23.1, 43, 53), and/or at least one external air extraction opening (13.1, 23.2, 23.3, 33.2, 49, 49.1, 54.2, 63) and/or - between at least one front air opening (12.2, 22, 35.3, 75.4s) provided by means of at least one end of said canalizations of said canalization structure, and at least one back air extraction opening (13, 33), provided by means of at least another end of said canalizations of said canalization structure, which structure at least partially occupies the interspace present between the head of a person wearing the helmet and said inner part (11.1, 21.1, 31.1, 41.1, 51.1, 61.1) of the helmet itself, characterized in that it comprises a cap (15, 25, 35, 45, 55, 65), which, when the helmet is worn by said person, cooperates with said padding to provide a plurality of air channels at said canalizations of said padding and covers the head of the person at least at the padding itself, while it is kept in tension on the head itself, pre- venting hair and organic material from occluding at least partially said air channels, and which is made of material that imbibes due to wettability and uniformly distributes at least part of the sweat of the head of the person, preventing it from being retained in said padding; in that said cap (15, 25, 35, 45, 55, 65) is dismountably connected with respect to said padding, respectively to said helmet, so that when removed, said cap allows inspection and cleaning of said air channels through which said air flow pass, and said air flows running through said channels determine a thermal conditioning and at least a partial extraction of moisture, at said cap (15, 25, 35, 45, 55, 65). - between said at least one frontal air intake opening (22.1, 52) and/or at least one external air intake opening (12.1, 22.4, 32.1, 42, 48.3, 54.1, 62) and said at least one back air extraction opening (23.1, 43, 53), and/or at least one external air extraction opening (13.1, 23.2, 23.3, 33.2, 49, 49.1, 54.2, 63) and/or - between at least one front air opening (12.2, 22, 35.3, 75.4s) provided by means of at least one end of said canalizations of said canalization structure, and at least one back air extraction opening (13, 33), provided by means of at least another end of said canalizations of said canalization structure, which structure at least partially occupies the interspace present between the head of a person wearing the helmet and said inner part (11.1, 21.1, 31.1, 41.1, 51.1, 61.1) of the helmet itself,