When my dad was a 12-year-old kid in Red Bluff, California, circa 1928, part of the extended family was a man he knew as Uncle Jack Cotney. That they knew of, or he'd admit to, Uncle Jack had survived some 25 stand-up gunfights in his life.
Green tea is a fat burner that does speed up the metabolism, as far as energy drinks however they really speed up the heart not your metabolism. If you're looking for something that will speed up your metabolism there are better choices for that. Good Luck, Casey.
Yes it does boost/speed up your metabolism, no it does not matter if it is hot or cold, but stop using the Snapple Brand because it is worse for you (look at the sugar content). I would suggest bagged green tea (find one that also has white tea) and brew your own - you can drink it either hot or cold.