One caveat: green tea comes in both caffeinated and decaffeinated. I like to have it iced so I make up a large pitcher and put it in the refrigerator. One time, not too long ago, I drank quite a bit that day. If I drink too much caffeine, I get a real burning in my stomach!
Also, someone else around here brought up the fact that you have to read your labels(again!) because not all green tea is created equal. It seems some of it has only "some" green tea" in it. (sigh)
As for lemon, I have always loved a good squirt of lemon in my iced tea. It is the stand by for iced tea drinkers. However, you might want to think twice about sticking the actual lemon wedge in your glass if you are out in a restaurant. It seems that there was a bacterial study done and lemon skins seems to be a magnet for germs and bacteria. I won't tell you what they found out but let's say, your toilet is cleaner. (yuck) So, if you have to squirt leave the lemon wedge on the dish besides the glass.
Time to brew a new pot!