Abstract: An article of headwear for covering the head, such as a hat, cap, or helmet, including coolant means for cooling the head of the wearer, and more particularly, cooling means which provide a prolonged cooling effect. The coolant means is contained in one or more pouches comprised of two layers of different materials, the first or outer material being a thin material having good thermal transmissive properties and preferably also having some water resistant properties, and the second or inner material provided interior of the first material and having thermal insulative properties. These layers, used in combination, have an effect of absorbing heat from the head of the wearer without at the same time absorbing excessive heat from the environment, and thus provide a sustained cooling effect. A heat releasing means can be substituted in place of the coolant means when it is desired to warm the head of the wearer.