It gives you the money depending on the official currency of the country where ATM is (like any other ATM machine), so in your case you will get dollars. I am from Croatia and I am getting our own currency ( Croatian kuna ) and next year we are getting euro so BTC ATMs will adjust accordingly.
Although it might seem like common sense, I never considered that would be possible. Since the exchanges I've used before ask for a lot of personal information for withdrawing to a bank (even just the bank info is a lot), getting cash from a BTC ATM is still blowing my mind!