The visible afterglow radiation from low‐pressure weakly ionized helium exhibits a partial quenching due to absorption of infrared photons (0.11–0.14 eV). The helium sample is placed in the cavity of aQ‐switched CO2laser and studied at gas temperatures in the range from 77 to 300°K. The partial quenching appears to originate from photon‐induced change of population of a state or states of a neutral or ionic helium molecule.