Any hat band has the potential to create a wear spot around the scalp. Heavy felt hats with leather bands may shrink if the temperature on the day drops significantly. These hats also limit the air flow about the scalp and often 'dam up' perspiration which further irritates.
Where hard hats are mandatory, adjust them for confort as well as safety and a cotton cap worn under the hat, a cotton band sewn over the original hat band, or thin foam attached to the band may offer a better degree of comfort.