A temperature changing device has a tubular member with a restricting portion that changes the air speed and pressure of liquids flowing there. An air inlet is provided to allow cooling or warming air to be drawn in and mix with the liquid in a mixing region. The air inlet is placed close to the bottom portion of the restricting portion. The restricting portion and inlet opening are placed far enough from the open top portion to allow for sufficient temperature change. In one embodiment, a stirring portion is provided to allow a user to stir a beverage such as coffee or tea.