When firefighters battle a blaze they face dangers seen and unseen. Although the fire itself is the immediate danger, many firefighters emerge with invisible maladies that may take years to manifest. According to the National Fire Protection Association, “a growing body of research and data shows the contributions that job-related exposures have in chronic illnesses, such as cancer and heart disease.” The report, launched in 2010 and verified in later years, found firefighters face a 9 percent increase in cancer diagnoses and a 14 percent increase in cancer-related deaths, compared to the general population in the U.S. The International Association…