Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of the detection of a continuous far red light stimulus by the high-irradiance response system. Far red light is electromagnetic radiation of wavelength 700-800nm. The activity of the high-irradiance response system is characterized by stronger effects of continuous than pulsed light at equal total fluence.