Removing candle wax from your favorite hat is easier if the hat is made of a natural fabric such as felt or wool than if the hat is made from a synthetic material like plastic or nylon. If the hat is a natural fiber, you can use a brown paper bag to "soak" up the candle wax by using a warm iron to loosen and melt the wax. If the hat is a synthetic material, you'll need to test an inconspicuous section of the hat first to ensure that the material won't melt under the heat of the clothes iron.
Place the hat onto the flat surface of the ironing board. If the hat is soft and easily crushed, insert as much of the towel as possible into the hat to give the hat some stuffing and extra support.
Place a brown paper bag over the candle wax.
Set the iron on a low setting and iron over the brown paper bag. The candle wax will melt, transferring to the paper bag and off of your hat.
Continue ironing the brown paper bag over the candle wax until the wax has been completely removed from the hat. If your hat is a synthetic material, you may try placing a very thin dish towel over the paper bag before ironing to absorb some of the heat. Generally, this method will require more time because less heat from the iron will reach the hat, but it's better to spend more time removing the wax than to melt your hat.