the 20th Century
In the early days of the Bureau of Mines, mine rescuers were called "helmet men" or "apparatus men." Their chief work was to investigate the cause of a mine disaster as quickly as possible, to assist in the rescue of miners, give first aid, and train miners in first aid and mine rescue techniques.
Persons receiving first aid training were instructed and examined in the anatomy of the human body, the treatment of hemorrhage, fractures, burns, and shock, and the transport of wounded persons. Certificates of rescue training were given to persons who passed a physical examination, showed ability to wear breathing apparatus while doing hard labor in atmospheres containing noxious or irrespirable gases, demonstrated their ability to adjust and take care of breathing apparatus, and perform the duties of rescue men.