I do not know if the potency would be the same as freshly made tea. You would certaintly not be harmed be drinking cool tea. I wouldn't keep refridgerated tea for more than 24 - 48 hours, I'm sure the longer you keep the less potent the tea will be. Could you prepare tea, then drink it once it hits room temperature? If not just make iced tea, just don't add sugar! :)