Here are the steps that I follow when I want a glass of iced tea quickly.
1. Fill a glass measuring cup with 1 cup (8 oz) of water. Heat in the microwave for 2 minutes. Obviously, YMMV.
2. Add one tea bag and step for 3-4 minutes.
3. Meanwhile, fill a 12 oz glass with ice cubes or half fill with crushed ice.
4. Add sweetner if desired to hot tea.
5. Pour hot tea over ice and stir until most of the ice has melted.
You can also double the water and tea bags for two glasses of tea. Please don't drink bottled tea, even if it's the only thing available. It's rotten.