Abstract: A helmet includes a concave interior surface forming an interior space configured to receive a person's head in an expanded configuration and a shell surrounding the interior space. The shell may include a first hinge at a first predetermined location on the shell configured to allow a first portion of the helmet to pivot toward the interior space in a collapsed configuration, and a second hinge at a second predetermined location configured to allow a second portion of the helmet to pivot toward the first portion of the helmet in the collapsed configuration.