Iced tea is a variety of Earth tea that has been chilled after steeping, rather than the more usual practice of serving the tea hot. Any flavor of tea can be served iced.
Both Captain Jonathan Archer and Commander Trip Tucker were fond of iced tea. (ENT: "Fight or Flight", et al.)
While aboard the Enterprise NX-01, Vulcan Ambassador V'Lar was introduced to iced tea, a variety flavored with passion fruit. She inquired to T'Pol if she ever tried it and she said that she did not care for it. V'Lar noted that Captain Archer certainly liked it. (ENT: "Fallen Hero")