Alchemist's Ice

This blue-white flask is cool to the touch because it contains a volatile liquid that turns to ice when exposed to air. If the flask is poured over a surface, it creates a 5-foot patch of ice that functions as regular ice for movement purposes. The flask can be thrown at a creature like a flask of alchemist's fire; if it hits, it does 1d8 cold damage and the creature must make a successful DC 10 Dexterity saving throw or its speed becomes 0 until the start of your next turn. Alchemist's ice was invented by alkemancers in the tropics as a way of keeping their food and drinks cold, and many restaurants and taverns still use it for this purpose. A vial of alchemist's ice costs 50 gp.