" This is quite daunting for me as I dont like cold drinks. Would fruit teas be ok? any other advice on this please"
Take the advice of your doctor, but as you asked for opinions, I will give you mine.
2 litres is just the medical profession guessing again , but in answer to your question, the 2 litres could be made up of milk, tea, water, fruit juice........etc.
Don't get "bogged down" with this "2 litres"....if you want my advice....drink when you feel like it.