Alchemist’s Ice (flask)

This sticky, adhesive fluid ignites into cold blue flames when exposed to air, which freeze into icicles. As an action, you can throw this flask up to 20 feet, shattering it on impact. Make a ranged attack against a creature or object, treating the alchemist's ice as an improvised weapon. On a hit, the target takes 1d4 cold damage at the start of each of its turns. A creature can end this damage by using its action to make a DC 10 Dexterity check to extinguish the flames/remove the icicles.