Duration: Concentration (hand seals maintained) + 10 min/level. Afterwards, the temperature gradually drifts back to normal.
Effect: The user can raise or lower ambient temperature of a fixed area by 5 °C/level over a few seconds. The insides of objects and creatures are not affected directly.
Unusual uses: If it increases the area in temperature quickly enough, it can be used as an instant-death technique at ~level 32. Failing that, it can be used as a city-destroyer technique.