Hats are beneficial both during the winter and summer months. In the winter, they help protect your head from the cold, preventing possible cold-related illnesses. In the summer and warmer months, hats protect the head and hair from dangerous UV rays of the sun. The assumption that wearing a hat is damaging to hair is a myth, however; regular use of hats may cause minor hair damage, which depends on the tightness of the hat and on the materials it is made of.
Wearing a hat does not cause damage to the hair, or at least, it doesn't cause major damage. However, this depends on the type of hat you wear. According to NHS, the National Health Service, it is a myth that you will lose hair if you regularly wear a hat, even if you wear this hat for long periods of time and very frequently. Your hair may get damaged, however, from very tight hats which put a lot of pressure on your hair by cutting off circulation. When wearing a tight hat, your hair can't breathe, and as a result it may get greasy at the roots but dry at the ends. Also, when the hat rubs against dry hair, it may cause it to break.
Hats may also have a slightly beneficial effect on the health of your hair. During cooler days, hats protect your hair and scalp from the cold and from snow. This is especially beneficial if you go outside with wet hair, which may get weak and become prone to breakage when in contact with the cold. In the warmer months, it is important to protect your hair and scalp from the rays of the sun, as well as from winds and sand if you are at the beach. Hats help prevent a possible sunburn on the scalp. The sun dries out hair, causes the color to fade, and may cause burns on your exposed scalp.
Hats have minor negative effects on your hair. They may cause hair to become greasy, both in hot, humid weather and in dry, winter weather. When hair gets greasy, the circulation of oxygen to your hair follicles may decrease. As a result, hair may fall out. Also, if hair becomes excessively greasy on a regular basis from constant hat wear, dirt and bacteria may be involved which also may lead to hair loss. Your scalp may also get sensitive from your hat, and minor frizz may be involved as well. Luckily, the chances are quite small that wearing a hat will lead to hair loss if you choose a hat that isn't too tight, and allow circulation so that your hair and scalp can breathe from time to time. Regular cleansing of the hair also helps prevent bacteria and removes dirt and oil from hair.
To protect the health of your hair, choose hats which aren't so tight to the point that they put pressure on your head. Your hat should feel comfortable and not be pressed against your head. When choosing straw hats, make sure the straw is tightly woven and smooth. Straw hats may easily pull on hair, making it break, if the straw is loose and sticks out of the hat. Also, if the weave of the straw isn't tight enough, sun will shine through it, hence minimizing the UV protection of the hat.