Thermal Prescience (3.5e Invocation)

For 24 hours, you gain the ability to view infrared radiation. This effectively grants you darkvision out to your normal visual range, though thermal vision is of poor quality and any target visible by thermal vision alone has a 20% miss chance from concealment. Unusually hot sources, such as a fire elemental or a human against an unusually cold backdrop, stand out and do not possess such miss chances. Reptilian creatures and certain animals are cold blooded and do not show up on thermal vision.

As a standard action you can focus and detect heat sources up to 1 mile/3 levels away. You learn the direction of the greatest heat sources and their approximate size, number, and location. You do not know what is causing the heat sources or their specific square. Your senses in either form can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, 3 feet of wood or dirt, or a sufficiently cold obstruction such as a chilled fog or a wall of ice blocks it.