A helmet has an inner liner made of foam material forming a body of the helmet. The inner liner has a convex outer surface and a concave inner surface defining a cavity for receiving the wearer's head. The inner liner has a plurality of beams extending from front to rear of the helmet and spaced apart to form vents therebetween, the vents being free of foam material between adjacent beams. Rigid bridge members are comolded with the inner liner to be partially concealed in the inner liner, the at least one bridge member having at least one bridge projecting out of the foam material of two adjacent beams and extending transversely in at least one of the vents. At least one strap is provided to attach the helmet to a wearer's head.