Steep tea 4 minutes in 4 ounces boiling water. Dissolve sugar in tea and cool completely (if you have time).
Halve the orange and peach, and pit the peach. Using a citrus press, juice the orange and peach. (If you don’t have a citrus press, you can squeeze the orange by hand and throw the pitted peach in the blender.) Add juices to a large cup filled with ice. Add the cooled tea. Fill any remaining space in the glass with cold water.