The Therinian Ice Age was an ice age which took place many centuries prior to the 24th century.

In 2373, after the USS Voyager was damaged by the shock wave of a supernova, the female Q was left on board the ship by Q, who had taken Voyager's commanding officer, Captain Kathryn Janeway with him to the Q Continuum. After sparring with Commander Chakotay, the female Q threatened to send Voyager back to the Therinian Ice Age, but was unable to as she had lost her powers due to the Q Civil War. (VOY: "The Q and the Grey")