To sew a scrub hat, first trace a circle with a 24-inch diameter onto fabric. Cut it out, fold the edges 1/2-inch and iron. Use a sewing machine to hem the entire edge of the circle and create a one inch opening, making sure to tuck the cut edges under the hem. Use a measuring tape to determine the circumference of the head. Measure from the forehead to the nape of the neck, including the area under the ears.
Transfer that measurement to a piece of elastic and cut it carefully. Insert the elastic into the opening of the fabric and pull it through until both ends meet. Sew the elastic ends together, and then sew the hem's opening closed.
Scrub caps are used to contain the hair of medical professionals and maintain the sterility of an operating room. While they can be purchased in medical supply stores, they can be easily made with customized fabric. Bouffant surgical caps are the most popular medical attire used in hospitals. These are single use only items that can be disposed of immediately after a procedure. Medical staff is required to wear either a scrub or bouffant cap during any medical procedure; patients receiving surgery are also required to wear bouffant caps to maintain a sterile field.