Bring water to a boil in a kettle; remove from heat. Add tea bags and steep for 5 minutes; remove tea bags.
Stir sugar into tea until dissolved. Cool to room temperature.
Fill 4 glasses with ice; pour tea into each glass until almost full. Stir 1 tablespoon sweetened condensed milk into each glass. Float 1 tablespoon half-and-half atop the iced tea.