Scalding gusts

Warlock Invocation
Level: Least, 2nd lv.
Components: V, S
Casting Time: 1 standard action
Range: Self
Duration: 24 hours
Saving Throw: Fort
Spell Resistance: No

You create a strong blast of wind (as the gust of wind spell, PH 238, except that the duration is instantaneous). Any creature within the effect takes 1 point of fire damage per caster level, regardless of whether it succeeds on the Fortitude save to avoid the gust.

(Complete Arcane, Page 134)