We report on a novel nonlinear laser spectroscopic technique for single-shot imaging of ground-state hydrogen atoms in harsh environments. H atoms from the ground state were first pumped to the $2s$ state via a two-photon excitation with a $243\mathrm{nm}$ laser beam, and the population of the $2s$ state was further probed through the $2s–4p$ transition with conventional polarization spectroscopy at $486\mathrm{nm}$ . A single $\mathrm{Nd}:\mathrm{YAG}$ -pumped optical parametric oscillator laser system was enough to provide both laser beams. Single-shot visualization of native H atoms in an atmospheric pressure premixed ${\mathrm{H}}_2∕{\mathrm{O}}_2$ flame is demonstrated.