Abstract of US 6760925 (B1)
Air-conditioned hardhats cool the wearer's head. A motor and fan are attached to the top of the interior of a hardhat to blow air over a coolant reservoir onto the wearer's head. The coolant reservoir can be filled with coolant. The bottom of the coolant reservoir comprises an atomizer, which allows the coolant to evaporatively cool the wearer's head. The motor is powered by a solar cell and/or a rechargeable battery. The rechargeable battery may be charged by a battery charger that is connected to the solar cell and can be optionally connected to an electrical outlet by a charging cord. A switch allows the user to control whether the motor is powered or not.
Abstract of US 4858627 (A)
A portable hat system enables the smoking of tobacco type products without affecting the environment includes a hat for covering the head of the smoker, an integral fan for intaking ambient air (contaminated and non contaminated) into the hat with this intake ambient air flowing in front of the smoker's face, a filtration, purification and deionization system for removal of combustion products, such as smoke odors and positive ions from the intake ambient air, and an exhaust system for expelling the filtered deodorized, deionized and optionally scented air from the hat.