In a survival scenario, it's easy to see how headwear can be beneficial. A good hat can shield your skin from the intense rays of the sun, stop sweat from running into your eyes, and help maintain your body temperature. On top of these benefits, apparel that covers your face provides additional protection from dust, and can even be used to conceal your identity in emergency situations.
For cold-weather settings, a wool or fleece balaclava (often called a “ski mask”) can be a great choice for full-face cover, but its form-fitting design will likely be stifling in summer heat. When temperatures rise into the triple-digits, you'll need something loose and breathable that still provides maximum protection. Enter the shemagh (a.k.a. keffiyeh), a square scarf which has been a prominent head covering in the Middle East region for centuries.
A shemagh is essentially just a large square of fabric, much like a bigger bandana. It's typically made of woven cotton for breathability, but cotton/wool blends and other synthetic fabrics are also available. You've probably seen them worn by insurgent forces in the Middle East, as well as by various western special-operations forces.
Whether you've already got a shemagh in your survival pack, or you're thinking about buying one in the future, it's helpful to know how to form this fabric square into a head covering. There are many methods, but the video below from Dakota Jennings on YouTube shows 7 useful styles.