Cold Comfort

The contraption called cold comfort is a watertight pouch filled with a handful of small, heavy, silvery pellets. When emptied into an adjacent body of water, the pellets freeze the water's surface almost instantly, creating an ice block in a 10-foot square to a depth of 1 foot. Any creatures inside this space must attempt a DC 23 Reflex save. On a failure, the creature takes 2d6 cold damage and is immobilized for 1 minute or until it Escapes (DC 20) or the ice is broken. The entire ice block has AC 10, Hardness 10, and 40 Hit Points, and it's immune to critical hits, cold damage, and precision damage.