When brewing black teas to serve cold, steep them longer than usual, as their intensity will be mellowed by ice and the addition of other flavors.
Pour water over tea, and steep for 5 to 7 minutes. Strain. Bring tea and sugar to a boil in a saucepan. Let cool. To serve, pour 1/2 cup tea over crushed ice in 8 glasses, and then top each with 1 tablespoon cream.