NewsAnimalsFevers link with specialized immunity is surprisingly ancientFevers boost survival and killing ability of T cells in fish Nile tilapia (one shown) seek warmer waters when sick, a behavior that kicks off their specialized adaptive immune system, a new study suggests.Luying WangBy McKenzie Prillaman13 seconds agoThe immune-boosting power of a fever is surprisingly ancient.Cold-blooded creatures like fish typically move to warmer environments to help fight infections. In one fish species, Nile tilapia, that behavioral or sought-out fever triggers the adaptive immune system, known for its acquired memory of specific bodily invaders, researchers report in the Dec. 24 Proceedings of the National Academy of Sciences. The finding hints that the link between fever and adaptive immunity arose long ago in animals evolutionary history, with a truly archaic common ancestor.