You can expend 1 charge as an action and use the ring to lower the temperature in a 120-foot-radius sphere centered on a point you can see within 300 feet of you. The temperature in that area drops 20 degrees per minute, to a minimum of -30 degrees Fahrenheit. Frost and ice begin to form on surfaces once the temperature drops below 32 degrees. This effect is permanent unless you use the ring to end it as an action, at which point the temperature in the area returns to normal at a rate of 10 degrees per minute.