Top: coronal radiation losses per hydrogen atom per electron (Λ_ν(T) in Eq. (2)) as function of temperature and wavelength. The scale is inverted, so black means large losses. Bottom: Λ_E, the frequency-integrated energy losses per hydrogen atom per electron (blue, arbitrary units); Λ_ph, the frequency-integrated photon losses per hydrogen atom per electron (black, scale on the left);Λ_csw, the frequency-integrated, He i ground-state continuum cross section weighted, photon losses per hydrogen atom per electron (red, arbitrary units).