You call forth the cold of the arctic regions, making movement and fighting difficult for the unprepared.
Prerequisite: Exposure to Cone of Cold or Ice Storm spell.
Benefit: Once per day, you can make the ground icy in a 200 foot-radius spread around you. Each square in the area becomes covered with ice, so it takes two squares of movement to enter each square, and the DC of Balance and Tumble checks there increases by 5. A DC 10 Balance check is required to run or charge across the ice.
The ice remains for 1 minute or until exposed to fire.
You can't use this feat is you aren't touching the ground, and it doesn't work if the air temperature is above 100 degrees.
Source: Unearthed Arcana