1. From Environmental & Occupational Medicine & Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (S.N.K.); Occupational Medicine, The Cambridge Health Alliance/Harvard Medical School, Cambridge, MA (S.N.K.); Health and Exercise Sciences, Skidmore College, Saratoga Springs, NY (D.L.S.); and University of Illinois Fire Service Institute, Champaign (D.L.S.).