Thank you very much for those references-good, thoughtful reading. I was most interested in the material on fire shelters. My first fire fighting season was 1956 and back then we had nothing in the way of protective clothing (other than hard hats). We all wore cotton routinely. Although fire fighting was an occasional job through the years, I didn't encounter fire shelters until the 1990s. By then everyone on the line was wearing Nomex.