If the surgical design allows wearing a light hat without touching the grafts, then a hat may be used immediately after a hair transplant. However, if a hairline procedure is done, it is not usually possible to wear a hat without risking these grafts at the hairline. It is best to wait a couple of days before a light hat is worn. A wooly hat may be worn 7-10 days later and cap may be used 2-3 weeks later.