Since straws rely on atmospheric pressure, they work less well at high altitudes. There is less pressure pushing down on your drink, and so less force pushing the drink up into your mouth.
Wholly unsurprisingly, the change has not been embraced by many of McDonald's loyal customers, and it turns out the new straws could actually be making your soft drinks taste different.
Cold drinks include iced energy drinks, cold coffees, Starbucks Refreshers, Frappuccino blended beverages, iced teas and lemonades. The straw will fit most reusable Starbucks cold cups.