Because of the limited understanding of chemical warfare during World War I, treatment options were limited and often involved little more than comforting and monitoring the persons subjected to an attack. Successful treatment of gassed patients depended heavily on early recognition of the condition, the patients’ removal from the gassed area, the determination of the gas type employed, and the prompt application of several different therapeutic measures. If it wasn’t practical to remove the patient from the gassed zone, a well-fitting gas mask was applied until the patient could be transported. Patients exposed to gas were under strict orders not to indulge in undue exertion, including walking, due to the stress and damage that many of the gases would cause to the lung tissue. Upon arriving at the hospital, patients would be classified according to the type of gas to which they had been exposed and the severity of their case.