A bike helmet is a protective headgear designed to reduce the risk of head injuries while riding a bicycle. It is typically made of a hard outer shell and an inner foam layer that absorbs impact. Helmets come in various styles and sizes to fit different head shapes and preferences, ensuring comfort and safety for riders of all ages. Wearing a bike helmet is often recommended by safety organizations and is required by law in some areas. Proper fitting is essential for effectiveness; the helmet should sit level on the head and not move when shaken. Regularly checking for damage and replacing old helmets is also important for maintaining safety standards.