Nocturnal beasts often see in the infrared spectrum–meaning they can “see” by detecting heat. Creatures with Infravision halve penalties (round down) for bad lighting when attacking living targets.

Clever characters may figure out ways to mask their heat from such creatures. Smearing cold mud over one's body or wearing special heat-filtering suits generally obscures the target from those with Infravision. Creatures with Infravision almost always have normal sight as well.

Savage Worlds Deluxe Edition p.