Tea... an important issue

Stewing tea is bad, by most accounts.

"Putting the tea in the water before you boil it will produce stewed tea. It's a very strong tea usually drunk with a lot of sugar. It's not to everyone's taste."
http://www.wikihow.com/Make-a-Good-Cup-of-Tea

Leaving the bag(s) in for about 4 hours will also stew tea. I learned the hard way the first time I made a thermos of tea for a really long ride. After 2 hours I thought, right my first stop of the day, I'll have a cup of tea and half a sandwich. I'd stupidly just poured water on top of 3 teabags, added milk and closed it up. I made the thermos about 2 hours before I left, hence the 4 hours in total. That tea tasted so strong I could have stood bread up in it.