The surface of the rice is considerably hot similarly to that of the boiled rice right after the boiling because only several minutes have passed after the steaming, therefore, it is sufficient to pat the surface of the rice with wet hands.
なお、蒸して数分しか経過していないので表面は炊きたてのご飯と同じに相当に熱いので、餅の表面を濡れた手のひらで叩く程度で良い。