The temporal shield was a variant on the conventional energy shields used by Starfleet vessels. Developed by the U.S.S. Voyager to combat the chroniton torpedoes of the Krenim. The temporal shields used a temporal variance field that negated the shield-penetrating abilities of chroniton torpedoes. It had the side-effect of leaving Voyager out of synch with normal space-time, allowing them to weather Annorax's changes to history without being altered themselves. This technology was lost when the Krenim Temporal Weapon Ship was destroyed and the changes it inflicted on history were undone.