Heretofore, many forms of liners have been proposed for use in hard hats. Some liners are resistant to heat and some are lined to protect the wearer from cold. The closest art known to me prior to this application are:
______________________________________ British Specification 239,371, of Sept. 10, 1925, British Specification 397,985, of Sept. 7, 1933, U.S. Pat. Nos. ______________________________________ 2,357,851 2,381,524 3,223,086 3,535,706 3,594,814 4,397,045 4,619,003 ______________________________________