You gain additional bonus spells in cold regions.
Prerequisites: Con 13, Snowcasting, Frozen Magic, Cold Focus.
Benefit: In cold areas (temperature at or below 40° F), the ability score used to determine how many bonus spells you may prepare or cast is treated as if it were 2 higher than its actual score. If you enter an area with a warmer temperature and remain in this area for longer than 1 minute, the bonus spells granted by this feat are lost until you can regain them.
In areas of extreme cold (below –20° F), the ability score is treated as if it were 4 higher than its actual score for purposes of determining how many bonus spells you can prepare or cast.
Source: Frostburn, page 48.